diff --git a/C4.puml b/C4.puml
index 154df47..2ec68f0 100644
--- a/C4.puml
+++ b/C4.puml
@@ -18,56 +18,61 @@ rectangle C4VersionDetailsArea <<legendArea>> [
 ' Colors
 ' ##################################
 
-!global $ELEMENT_FONT_COLOR = "#FFFFFF"
+!$ELEMENT_FONT_COLOR ?= "#FFFFFF"
 
-!global $ARROW_COLOR = "#666666"
+!$ARROW_COLOR ?= "#666666"
 
-!global $BOUNDARY_COLOR = "#444444"
-!global $BOUNDARY_BG_COLOR = "transparent"
+!$BOUNDARY_COLOR ?= "#444444"
+!$BOUNDARY_BG_COLOR ?= "transparent"
 
-!global $LEGEND_FONT_COLOR = "#FFFFFF"
-!global $LEGEND_TITLE_COLOR = "#000000"
+!$LEGEND_FONT_COLOR ?= "#FFFFFF"
+!$LEGEND_TITLE_COLOR ?= "#000000"
 ' %darken(darkkhaki,50), #khaki
-!global $LEGEND_DARK_COLOR = "#66622E"
-!global $LEGEND_LIGHT_COLOR = "#khaki"
+!$LEGEND_DARK_COLOR ?= "#66622E"
+!$LEGEND_LIGHT_COLOR ?= "#khaki"
 
-!global $SKETCH_BG_COLOR = "#EEEBDC" 
-!global $SKETCH_FONT_COLOR = ""
-!global $SKETCH_WARNING_COLOR = "red"
-!global $SKETCH_FONT_NAME = "Comic Sans MS"
+!$SKETCH_BG_COLOR ?= "#EEEBDC" 
+!$SKETCH_FONT_COLOR ?= ""
+!$SKETCH_WARNING_COLOR ?= "red"
+!$SKETCH_FONT_NAME ?= "Comic Sans MS"
 
 ' Labels
 ' ##################################
 
-!global $LEGEND_SHADOW_TEXT = "shadow"
-!global $LEGEND_NO_SHADOW_TEXT = "no shadow"
-!global $LEGEND_NO_FONT_BG_TEXT = "last text and back color"
-!global $LEGEND_NO_FONT_TEXT = "last text color"
-!global $LEGEND_NO_BG_TEXT = "last back color"
-!global $LEGEND_NO_LINE_TEXT = "last line color"
-!global $LEGEND_ROUNDED_BOX = "rounded box"
-!global $LEGEND_EIGHT_SIDED = "eight sided"
-!global $LEGEND_DOTTED_LINE = "dotted"
-!global $LEGEND_DASHED_LINE = "dashed"
-!global $LEGEND_BOLD_LINE = "bold"
-!global $LEGEND_BOUNDARY = "boundary"
-!global $LEGEND_DASHED_BOUNDARY = "dashed"
+!$LEGEND_SHADOW_TEXT ?= "shadow"
+!$LEGEND_NO_SHADOW_TEXT ?= "no shadow"
+!$LEGEND_NO_FONT_BG_TEXT ?= "last text and back color"
+!$LEGEND_NO_FONT_TEXT ?= "last text color"
+!$LEGEND_NO_BG_TEXT ?= "last back color"
+!$LEGEND_NO_LINE_TEXT ?= "last line color"
+!$LEGEND_ROUNDED_BOX ?= "rounded box"
+!$LEGEND_EIGHT_SIDED ?= "eight sided"
+!$LEGEND_DOTTED_LINE ?= "dotted"
+!$LEGEND_DASHED_LINE ?= "dashed"
+!$LEGEND_BOLD_LINE ?= "bold"
+!$LEGEND_BOUNDARY ?= "boundary"
+!$LEGEND_DASHED_BOUNDARY ?= "dashed"
 ' ignore transparent atm, that the legend is smaller
-'!global $LEGEND_DASHED_TRANSPARENT_BOUNDARY = "dashed, transparent"
-!global $LEGEND_DASHED_TRANSPARENT_BOUNDARY = "dashed"
+'$LEGEND_DASHED_TRANSPARENT_BOUNDARY ?= "dashed, transparent"
+!$LEGEND_DASHED_TRANSPARENT_BOUNDARY ?= "dashed"
 
-!global $SKETCH_FOOTER_WARNING = "Warning:"
-!global $SKETCH_FOOTER_TEXT = "Created for discussion, needs to be validated"
+!$SKETCH_FOOTER_WARNING ?= "Warning:"
+!$SKETCH_FOOTER_TEXT ?= "Created for discussion, needs to be validated"
 
 ' Styling
 ' ##################################
 
-!global $TECHN_FONT_SIZE = 12
-!global $ROUNDED_BOX_SIZE = 25
-!global $EIGHT_SIDED_SIZE = 18
+!$STEREOTYPE_FONT_SIZE ?= 12
+!global $TRANSPARENT_STEREOTYPE_FONT_SIZE = $STEREOTYPE_FONT_SIZE/2
 
-!global $LEGEND_DETAILS_SMALL_SIZE = 10
-!global $LEGEND_DETAILS_NORMAL_SIZE = 14
+!$TECHN_FONT_SIZE ?= 12
+!$ROUNDED_BOX_SIZE ?= 25
+!$EIGHT_SIDED_SIZE ?= 18
+
+!$ARROW_FONT_SIZE ?= 12
+
+!$LEGEND_DETAILS_SMALL_SIZE ?= 10
+!$LEGEND_DETAILS_NORMAL_SIZE ?= 14
 !global $LEGEND_DETAILS_SIZE = $LEGEND_DETAILS_SMALL_SIZE
 
 !global $ROUNDED_BOX = "roundedBox"
@@ -91,40 +96,39 @@ skinparam LegendBackgroundColor transparent
 skinparam LegendFontColor $LEGEND_FONT_COLOR
 
 skinparam shadowing<<legendArea>> false
-' #00000000 is transparent
 skinparam rectangle<<legendArea>> {
-    backgroundcolor #00000000
-    bordercolor #00000000
+    backgroundcolor transparent
+    bordercolor transparent
 }
 
 skinparam rectangle {
-    StereotypeFontSize 12
+    StereotypeFontSize $STEREOTYPE_FONT_SIZE
     shadowing false
 }
 
 skinparam database {
-    StereotypeFontSize 12
+    StereotypeFontSize $STEREOTYPE_FONT_SIZE
     shadowing false
 }
 
 skinparam queue {
-    StereotypeFontSize 12
+    StereotypeFontSize $STEREOTYPE_FONT_SIZE
     shadowing false
 }
 
 skinparam arrow {
     Color $ARROW_COLOR
     FontColor $ARROW_COLOR
-    FontSize 12
+    FontSize $ARROW_FONT_SIZE
 }
 
 skinparam person {
-    StereotypeFontSize 12
+    StereotypeFontSize $STEREOTYPE_FONT_SIZE
     shadowing false
 }
 
 skinparam actor {
-    StereotypeFontSize 12
+    StereotypeFontSize $STEREOTYPE_FONT_SIZE
     shadowing false
     style awesome
 }
@@ -133,13 +137,13 @@ skinparam actor {
 ' UpdateBoundaryStyle() called in boundary section below
 skinparam rectangle<<boundary>> {
     Shadowing false
-    StereotypeFontSize 6
+    StereotypeFontSize $TRANSPARENT_STEREOTYPE_FONT_SIZE
     StereotypeFontColor $BOUNDARY_BG_COLOR
     BorderStyle dashed
 }
 
 skinparam package {
-    StereotypeFontSize 6
+    StereotypeFontSize $TRANSPARENT_STEREOTYPE_FONT_SIZE
     StereotypeFontColor $BOUNDARY_BG_COLOR
     FontStyle plain
     BackgroundColor $BOUNDARY_BG_COLOR
@@ -538,6 +542,7 @@ $elementSkin
   !endif
   !if ($legendText == "")
     !if ($tagStereo == "boundary")
+      ' #00000000 is transparent
       !if ($bgColor == "#00000000" || %lower($bgColor) == "transparent")
         !$tagEntry = $tagEntry + " " + $LEGEND_BOUNDARY + " "
         !$tagDetails = $tagDetails + $LEGEND_DASHED_TRANSPARENT_BOUNDARY + ", "
@@ -1039,6 +1044,7 @@ hide stereotype
 
 !procedure $getLegendTable($detailsFormat)
 !global $LEGEND_DETAILS_SIZE = $getLegendDetailsSize($detailsFormat)
+' #00000000 is transparent, but transparent is not working
 <#00000000,#00000000>|<color:$LEGEND_TITLE_COLOR>**Legend**</color> |
 $showActiveLegendEntries($tagDefaultLegend)
 $showActiveLegendEntries($tagCustomLegend)
diff --git a/C4_Component.puml b/C4_Component.puml
index ace0e0b..53f852f 100644
--- a/C4_Component.puml
+++ b/C4_Component.puml
@@ -13,18 +13,19 @@
 ' Colors
 ' ##################################
 
-!global $COMPONENT_FONT_COLOR = "#000000"
+!$COMPONENT_FONT_COLOR ?= "#000000"
+!$COMPONENT_BG_COLOR ?= "#85BBF0"
+!$COMPONENT_BORDER_COLOR ?= "#78A8D8"
 
-!global $COMPONENT_BG_COLOR = "#85BBF0"
-!global $COMPONENT_BORDER_COLOR = "#78A8D8"
-!global $EXTERNAL_COMPONENT_BG_COLOR = "#CCCCCC"
-!global $EXTERNAL_COMPONENT_BORDER_COLOR = "#BFBFBF"
+!$EXTERNAL_COMPONENT_FONT_COLOR ?= $COMPONENT_FONT_COLOR
+!$EXTERNAL_COMPONENT_BG_COLOR ?= "#CCCCCC"
+!$EXTERNAL_COMPONENT_BORDER_COLOR ?= "#BFBFBF"
 
 ' Styling
 ' ##################################
 
 UpdateElementStyle("component", $COMPONENT_BG_COLOR, $COMPONENT_FONT_COLOR, $COMPONENT_BORDER_COLOR)
-UpdateElementStyle("external_component", $EXTERNAL_COMPONENT_BG_COLOR, $COMPONENT_FONT_COLOR, $EXTERNAL_COMPONENT_BORDER_COLOR)
+UpdateElementStyle("external_component", $EXTERNAL_COMPONENT_BG_COLOR, $EXTERNAL_COMPONENT_FONT_COLOR, $EXTERNAL_COMPONENT_BORDER_COLOR)
 
 ' shortcuts with default colors
 !unquoted procedure AddComponentTag($tagStereo, $bgColor="", $fontColor="", $borderColor="", $shadowing="", $shape="", $sprite="", $techn="", $legendText="", $legendSprite="")
diff --git a/C4_Container.puml b/C4_Container.puml
index 2166467..1cc0bc2 100644
--- a/C4_Container.puml
+++ b/C4_Container.puml
@@ -13,15 +13,18 @@
 ' Colors
 ' ##################################
 
-!global $CONTAINER_BG_COLOR = "#438DD5"
-!global $CONTAINER_BORDER_COLOR = "#3C7FC0"
-!global $EXTERNAL_CONTAINER_BG_COLOR = "#B3B3B3"
-!global $EXTERNAL_CONTAINER_BORDER_COLOR = "#A6A6A6"
+!$CONTAINER_FONT_COLOR ?= $ELEMENT_FONT_COLOR
+!$CONTAINER_BG_COLOR ?= "#438DD5"
+!$CONTAINER_BORDER_COLOR ?= "#3C7FC0"
+
+!$EXTERNAL_CONTAINER_FONT_COLOR ?= $ELEMENT_FONT_COLOR
+!$EXTERNAL_CONTAINER_BG_COLOR ?= "#B3B3B3"
+!$EXTERNAL_CONTAINER_BORDER_COLOR ?= "#A6A6A6"
 
 ' Styling
 ' ##################################
-UpdateElementStyle("container", $CONTAINER_BG_COLOR, $ELEMENT_FONT_COLOR, $CONTAINER_BORDER_COLOR)
-UpdateElementStyle("external_container", $EXTERNAL_CONTAINER_BG_COLOR, $ELEMENT_FONT_COLOR, $EXTERNAL_CONTAINER_BORDER_COLOR)
+UpdateElementStyle("container", $CONTAINER_BG_COLOR, $CONTAINER_FONT_COLOR, $CONTAINER_BORDER_COLOR)
+UpdateElementStyle("external_container", $EXTERNAL_CONTAINER_BG_COLOR, $EXTERNAL_CONTAINER_FONT_COLOR, $EXTERNAL_CONTAINER_BORDER_COLOR)
 
 UpdateBoundaryStyle("container", $bgColor=$BOUNDARY_BG_COLOR, $fontColor=$BOUNDARY_COLOR, $borderColor=$BOUNDARY_COLOR, $type="Container")
 
diff --git a/C4_Context.puml b/C4_Context.puml
index 700ae5d..f6b80bb 100644
--- a/C4_Context.puml
+++ b/C4_Context.puml
@@ -13,22 +13,29 @@
 ' Colors
 ' ##################################
 
-!global $PERSON_BG_COLOR = "#08427B"
-!global $PERSON_BORDER_COLOR = "#073B6F"
-!global $EXTERNAL_PERSON_BG_COLOR = "#686868"
-!global $EXTERNAL_PERSON_BORDER_COLOR = "#8A8A8A"
-!global $SYSTEM_BG_COLOR = "#1168BD"
-!global $SYSTEM_BORDER_COLOR = "#3C7FC0"
-!global $EXTERNAL_SYSTEM_BG_COLOR = "#999999"
-!global $EXTERNAL_SYSTEM_BORDER_COLOR = "#8A8A8A"
+!$PERSON_FONT_COLOR ?= $ELEMENT_FONT_COLOR
+!$PERSON_BG_COLOR ?= "#08427B"
+!$PERSON_BORDER_COLOR ?= "#073B6F"
+
+!$EXTERNAL_PERSON_FONT_COLOR ?= $ELEMENT_FONT_COLOR
+!$EXTERNAL_PERSON_BG_COLOR ?= "#686868"
+!$EXTERNAL_PERSON_BORDER_COLOR ?= "#8A8A8A"
+
+!$SYSTEM_FONT_COLOR ?= $ELEMENT_FONT_COLOR
+!$SYSTEM_BG_COLOR ?= "#1168BD"
+!$SYSTEM_BORDER_COLOR ?= "#3C7FC0"
+
+!$EXTERNAL_SYSTEM_FONT_COLOR ?= $ELEMENT_FONT_COLOR
+!$EXTERNAL_SYSTEM_BG_COLOR ?= "#999999"
+!$EXTERNAL_SYSTEM_BORDER_COLOR ?= "#8A8A8A"
 
 ' Styling
 ' ##################################
 
-UpdateElementStyle("person", $PERSON_BG_COLOR, $ELEMENT_FONT_COLOR, $PERSON_BORDER_COLOR)
-UpdateElementStyle("external_person", $EXTERNAL_PERSON_BG_COLOR, $ELEMENT_FONT_COLOR, $EXTERNAL_PERSON_BORDER_COLOR)
-UpdateElementStyle("system", $SYSTEM_BG_COLOR, $ELEMENT_FONT_COLOR, $SYSTEM_BORDER_COLOR)
-UpdateElementStyle("external_system", $EXTERNAL_SYSTEM_BG_COLOR, $ELEMENT_FONT_COLOR, $EXTERNAL_SYSTEM_BORDER_COLOR)
+UpdateElementStyle("person", $PERSON_BG_COLOR, $PERSON_FONT_COLOR, $PERSON_BORDER_COLOR)
+UpdateElementStyle("external_person", $EXTERNAL_PERSON_BG_COLOR, $EXTERNAL_PERSON_FONT_COLOR, $EXTERNAL_PERSON_BORDER_COLOR)
+UpdateElementStyle("system", $SYSTEM_BG_COLOR, $SYSTEM_FONT_COLOR, $SYSTEM_BORDER_COLOR)
+UpdateElementStyle("external_system", $EXTERNAL_SYSTEM_BG_COLOR, $EXTERNAL_SYSTEM_FONT_COLOR, $EXTERNAL_SYSTEM_BORDER_COLOR)
 
 UpdateBoundaryStyle("enterprise", $bgColor=$BOUNDARY_BG_COLOR, $fontColor=$BOUNDARY_COLOR, $borderColor=$BOUNDARY_COLOR, $type="Enterprise")
 UpdateBoundaryStyle("system", $bgColor=$BOUNDARY_BG_COLOR, $fontColor=$BOUNDARY_COLOR, $borderColor=$BOUNDARY_COLOR, $type="System")
diff --git a/C4_Deployment.puml b/C4_Deployment.puml
index 80f9bf2..4aa7a0f 100644
--- a/C4_Deployment.puml
+++ b/C4_Deployment.puml
@@ -8,9 +8,9 @@
 ' Colors
 ' ##################################
 
-!global $NODE_FONT_COLOR = "#000000"
-!global $NODE_BG_COLOR = "#FFFFFF"
-!global $NODE_BORDER_COLOR = "#A2A2A2"
+!$NODE_FONT_COLOR ?= "#000000"
+!$NODE_BG_COLOR ?= "#FFFFFF"
+!$NODE_BORDER_COLOR ?= "#A2A2A2"
 
 ' Styling
 ' ##################################
diff --git a/LayoutOptions.md b/LayoutOptions.md
index 4297af8..2faf74d 100644
--- a/LayoutOptions.md
+++ b/LayoutOptions.md
@@ -18,6 +18,7 @@ C4-PlantUML comes with some layout options.
     - [Using SHOW_PERSON_SPRITE(sprite)](#using-show_person_spritesprite)
     - [Using SHOW_PERSON_PORTRAIT()](#using-show_person_portrait)
     - [Using SHOW_PERSON_OUTLINE()](#using-show_person_outline)
+- [📄 Themes (WIP), Changeable Styles](#themes-wip-changeable-styles)
 - samples
   - [📄 Core Diagrams](samples/C4CoreDiagrams.md#c4-model-diagrams)
 
diff --git a/README.md b/README.md
index 12811ff..111d1ad 100644
--- a/README.md
+++ b/README.md
@@ -41,7 +41,7 @@ C4-PlantUML includes macros, stereotypes, and other goodies (like VSCode Snippet
     - [Sample with different tag combinations](#sample-with-different-tag-combinations)
     - [Sample with tag dependent sprites and custom legend text](#sample-with-tag-dependent-sprites-and-custom-legend-text)
     - [Sample with different boundary tag combinations](#sample-with-different-boundary-tag-combinations)
-    - [Custom schema definition](#custom-schema-definition)
+    - [Custom schema definitions (via UpdateElementStyle())](#custom-schema-definitions-via-updateelementstyle)
   - [Element and Relationship properties](#element-and-relationship-properties)
   - [Version information](#version-information)
   - [Snippets for Visual Studio Code](#snippets-for-visual-studio-code)
@@ -55,6 +55,7 @@ C4-PlantUML includes macros, stereotypes, and other goodies (like VSCode Snippet
   - [Background](#background)
   - [License](#license)
 - [📄 Layout Options](LayoutOptions.md#layout-options)
+- [📄 Themes (WIP), Changeable Styles](Themes.md#themes-wip-changeable-styles)
 - samples
   - [📄 Core Diagrams](samples/C4CoreDiagrams.md#c4-model-diagrams)
 
@@ -567,7 +568,7 @@ Multiple tags can be combined with `+`, like `Container(api, "API", $tags="v1.0+
 Sometimes an added element tag is element specific and all element specific colors should be used, e.g. a specific user role should be defined as element tag with the specific colors `...PERSON_...` like
 
 ```plantuml
-AddElementTag("admin", $fontColor=$ELEMENT_FONT_COLOR, $bgColor=$PERSON_BG_COLOR, $borderColor=$PERSON_BORDER_COLOR, $sprite="osa_user_audit", $legendText="administration user")
+AddElementTag("admin", $fontColor=$PERSON_FONT_COLOR, $bgColor=$PERSON_BG_COLOR, $borderColor=$PERSON_BORDER_COLOR, $sprite="osa_user_audit", $legendText="administration user")
 ```
 
 Therefore element Add...Tag() shortcuts are added which use the specific colors as default values and the call can be simplified like
@@ -764,14 +765,18 @@ SHOW_LEGEND()
 
 ![custom border tags](https://www.plantuml.com/plantuml/png/bLHHRzem47xFhxX5bKYa0ghKfqr8fO3QXm8Lj9hwX9puIAmcTcGxfMZQVvyF4vg6RTgUsllkxlEN--wuCPPfMvT5y4N8jAWvGcvjPRuEXvhj1fcmUPtK1dMgf4Lf1wagXrN19FNqZUM5I8QJw_uZGS_pXs79Z4NjeCr4bPMIr5CHVz23vuepYs1pX0mbQf52ech9cTw3iVi2WKb-I8TcxsZAy192Hu2wqi8WHII32TSRDgq2ZMysO9KA_1ktHzer9QAB99keGkbHcAc2EvgBhQCvGebMEqbOeZH7_GcDdUXeXVtOivg3DY-jezny0urzWnQQnu2zAS4Dz2Af867fAwG4npqG4WhCKFAMuFM1z3zaxt9XiIExGUCWQ9YYn0rj34qOnl0Z-1a4asQCcrDXwYjFcRCUB_6ZmVW63vzLzu3Zrl4OO21n1rxcqMPQjK4RjliAWp7d3SiJow9GOwMCiCgHNa9h61fH_liq23KvusedP3OAhQuRg48OmOfUHFVm-vgGA7OvKZCAxuIzhnDegMZFDRrUeMaoRX1_kOcGA5bcHkqleZ41d6uaqiZu71tHQZQUpcU3aWmFvqo_Sh-9DDEFfIC-O9f6QL5BLXHxm7UBz2sm4pQ7tgOfxe7DcGLXeJO7FxZORb6Zj21PYM0gbc90LS80IfOKQ5erM619VvdatQM7hTB-9eZ7QIB2SoFVhZuPM8WijxzpqMDT5pqQ4-lCI_aZgSRkcH3I9IIiRIMJokQecvYscf3s2PoMudRvl9YELo_mzF8uEnbBOZg6Dgmde4LxmWu4cEPo54wMyyVbOhPuEcEc_pcQr2dtZLqpoDQMNwwlvQlnvYVkPNYxydkJCjdfyNRwBNjW-ysAVZVI93u6gOkCYmxXz91hht_SD7MEeZDOLxQ-NtxVFCpkPejf50StABaxcLy0 "custom border tags")
 
-### Custom schema definition
+### Custom schema definitions (via UpdateElementStyle())
 
-If the custom (color) schema is defined via `UpdateElementStyle()` then the legend of existing elements is updated too.
+Via `UpdateElementStyle()` calls is it possible to change the default colors, sprites, legend text, tags,...
+It updates automatically the legend too.  
+If the corresponding section is stored in a separate file then it can be reused as default of all diagrams.
 
 ```plantuml
 @startuml
 !include https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/C4_Context.puml
 
+' <<<<< this section could be stored in a separate file and reused in all other diagrams too
+' it defines new default colors, different default sprites and legend 
 !$COLOR_A_5 = "#7f3b08"
 !$COLOR_A_4 = "#b35806"
 !$COLOR_A_3 = "#e08214"
@@ -786,11 +791,12 @@ If the custom (color) schema is defined via `UpdateElementStyle()` then the lege
 !$COLOR_REL_LINE = "#8073ac"
 !$COLOR_REL_TEXT = "#8073ac"
 
-UpdateElementStyle("person", $bgColor=$COLOR_A_5, $fontColor=$COLOR_NEUTRAL, $borderColor=$COLOR_A_1, $shadowing="true")
-UpdateElementStyle("external_person", $bgColor=$COLOR_B_5, $fontColor=$COLOR_NEUTRAL, $borderColor=$COLOR_B_1)
-UpdateElementStyle("system", $bgColor=$COLOR_A_4, $fontColor=$COLOR_NEUTRAL, $borderColor=$COLOR_A_2)
-UpdateElementStyle("external_system", $bgColor=$COLOR_B_4, $fontColor=$COLOR_NEUTRAL, $borderColor=$COLOR_B_2)
+UpdateElementStyle("person", $bgColor=$COLOR_A_5, $fontColor=$COLOR_NEUTRAL, $borderColor=$COLOR_A_1, $shadowing="true", $legendText="Internal user")
+UpdateElementStyle("external_person", $bgColor=$COLOR_B_5, $fontColor=$COLOR_NEUTRAL, $borderColor=$COLOR_B_1, $legendText="External user")
+UpdateElementStyle("system", $bgColor=$COLOR_A_4, $fontColor=$COLOR_NEUTRAL, $borderColor=$COLOR_A_2, $sprite="robot", $legendText="Our chatbot based system")
+UpdateElementStyle("external_system", $bgColor=$COLOR_B_4, $fontColor=$COLOR_NEUTRAL, $borderColor=$COLOR_B_2, $legendText="External system")
 UpdateRelStyle($lineColor=$COLOR_REL_LINE, $textColor=$COLOR_REL_TEXT)
+' >>>>> end of section
 
 Person(customer, "Personal Banking Customer")
 System(banking_system, "Internet Banking System")
@@ -807,7 +813,7 @@ SHOW_LEGEND()
 @enduml
 ```
 
-![custom schema](https://www.plantuml.com/plantuml/png/dL9TRzem57tFhqWp7a0g448eqIIaDYpQAgLGyQ7jBRBZ2qHr76GxQlllvyJPuhRf9Y5UoBddt7lElRuL4d5PvjIwobXAImBsISgp-3eUS_GyEcRoLE9I04yB9e79KLhaupD5hD8CXIGqm-EbFtoieFr3FCwHaC0Lb2mhnOiSdQlkrbLlkOxNc-GkcTaBs_aoFqon6pW6xjSudiu2zyR4fpKERk1DV1FtQln0S70pDV69nW5SRFHPHVlTvYxMjNdrQsjXeo41GO1DNC_07iB4Ct7jAN3dKvIQkCumyxrv49YupkmHr_MD_fieJkBxLTJHJ1TtqQ_TcwArFnCa8QAG0vDR-KgXxvo1Yu8vrtOF7vS5BVYYtRK23-eEBTokek8Nd01_fvceWZWXKZndxBXm92_16NGELjS5pX1DFdKGNk10NQDxd7WL4lBEdFu5ERt_XFfqN7Z1kB0Tjm6gH_Leni1WjGz2zP3AXr5htyF0iXxhTVVJKiWY1tvjEnf1r0uHUr9divTDJLrkM-VeOrrfOYdDFQk2WlohqKIbQ2H9z2BxESfeguc6rRSj6kOx8Zjmb8EYFVpvtz5RnJUSVt2r5o0KJR6I4ALF1lMjaoqm8coe_GXR5erc1TdnfFR_8Uu_r5hQfT0XMbVMziVwPn97twFLj_x0kbLTofp-1W00 "custom schema")
+![custom schema](https://www.plantuml.com/plantuml/png/dLJlJ-904FtUlsBicHmcAbXGcijnKRZcpWJ1y2DttvfjTmgDsrsoEututz-MHIs8PsBvGFlUl9StivEzDiGqbONmZdAPYf8ZB8bMvbkpgTdZ-IAdPPcK1dMg9A6ayrGLpPLWijAS6U8YJvg3pjbz1StlXis26K9jeNXGATPqlghSlQ_mlNg0bha1WodbIaAgIi4XGJ2aD7B89J1BhfXcX93b0e593XfBisM504LBrC1pjj2iC41AMVESW6EMIpGWyR5wPwKWI9LGsfpQwYn3RVE_C6QbSqApyHUuGFld7HqFniFn9Bw9Bw47_fTkravQeL_3EniyQL-6hQiwtjxWs0g3YquT3pPunfFmgbt7BnoEs4fgFgDeFflS31tNhNwlN7-huI5dcDJnm6KAMCA3EkuoXQrkcwLrtFLmsGcwOLZ7NSy1RxKwDVz9D8o7jwFeW9aZPz7VsGxfpLUS4KO22vGqfIU13N-5sYZfdy9niXXKXz9xdRK5CoN9mRkZgEgLvgZtD1UMC4l6rMCk5psVT8cLjpl86QwfvzzAGYsPW6fx_PE3gN3jQk9tu_K_4SyUrLwMQFrn5lDa28k34-fyOaA19ToEztoj4aNxyncN6j8b8qj1mWnoS0a-6jMxEVkVo6ctzxrHxQMPe719ZaKkqPdihQXr8klXkBqDFR5tn8_g0PGSLFPy1NdU_URe6sbfI1MeJy5tY8tGP_B1xXSCjfmDCzsaQYIEsGx3Qjos8Rrefi_njvBODjOeM2vUDT6P_QurkbieCyqAj6Ltp-y7lErKQidVf9eRDBRCLiLzbZxKIdUJJ55o0xZ9Ou3KLZF2VB5CbDvhzxzg9tshg3MqJULDVu__nCFeLpJwsJZnhgrBMOX_ "custom schema")
 
 ## Element and Relationship properties
 
diff --git a/Themes.md b/Themes.md
new file mode 100644
index 0000000..35f831b
--- /dev/null
+++ b/Themes.md
@@ -0,0 +1,130 @@
+# Themes (WIP), Changeable Styles
+
+WIP: C4-PlantUML offers no finished themes (atm).
+It is possible to define/use custom themes.
+
+- [📄 C4-PlantUML](README.md#c4-plantuml)
+- [📄 Layout Options](#layout-options)
+- [📄 Themes (WIP), Changeable Styles](#themes-wip-changeable-styles)
+  - [Overall Guidance](#overall-guidance)
+  - [List of available C4-themes](#list-of-available-c4-themes)
+  - [How to write custom theme](#how-to-write-custom-theme)
+    - [Following variables could be set in theme definitions too](#following-variables-could-be-set-in-theme-definitions-too)
+- samples
+  - [📄 Core Diagrams](samples/C4CoreDiagrams.md#c4-model-diagrams)
+
+## Overall Guidance
+
+WIP ...
+
+```plantuml
+@startuml
+!theme C4_FirstTest from https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/themes
+!include https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/C4_Component.puml
+
+Person_Ext(customer, "Customer", "A customer of Widgets Limited.")
+
+Enterprise_Boundary(c0, "Widgets Limited") {
+    Person(csa, "Customer Service Agent", "Deals with customer enquiries.")
+    System(ecommerce, "E-commerce System", "Allows customers to buy widgts online via the widgets.com website.")
+    System(fulfilment, "Fulfilment System", "Responsible for processing and shipping of customer orders.")
+}
+
+System_Ext(taxamo, "Taxamo", "Calculates local tax (for EU B2B customers) and acts as a front-end for Braintree Payments.")
+System_Ext(braintree, "Braintree Payments", "Processes credit card payments on behalf of Widgets Limited.")
+System_Ext(post, "Jersey Post", "Calculates worldwide shipping costs for packages.")
+
+Rel_R(customer, csa, "Asks questions to", "Telephone")
+Rel_R(customer, ecommerce, "Places orders for widgets using")
+Rel(csa, ecommerce, "Looks up order information using")
+Rel_R(ecommerce, fulfilment, "Sends order information to")
+Rel_D(fulfilment, post, "Gets shipping charges from")
+Rel_D(ecommerce, taxamo, "Delegates credit card processing to")
+Rel_L(taxamo, braintree, "Uses for credit card processing")
+Lay_D(customer, braintree)
+
+SHOW_LEGEND()
+@enduml
+```
+
+![Theme sample](//www.plantuml.com/plantuml/png/hL9DRnen4BtlhvXm0gc4gigffuIFfAfeY_AX797n3c35Qsyyun1KzRztZ0auDCSY3lPwtdipRzubiGeS6rkTyHeRXD75_De4udiaXcNm3QoPM_ew60IrELyPNiT590pQEqR7vzetWzOgbpZwnBKrYy7eeZzBdnv-J0UD8iOms95JTMQSjh76_qCglOvyqtgNC6qQeffX8E_carVkwaZi6moVe3FQ7pjoleAt1_1BU3Jr2fbWQXh3M9ztUbKrSOoX3OPmFlJHrIfik_gpG4-AEptuNO7yicXNaogqu0x3Yz48Lojqd9J7g2p1HgOzje3kEPfWa99ouhhR4cFJHR50tZKARj9_k-nVTsDOwpTq829W3ukuXOtqo0JUMUCGNem2iHuskVDaB6nmGORnH70PxTBO1XqB-VNXKYZU8edLP1OMOUa3jC5h939k1ShLG6lJjkdYbuN3eSQmc-rFLMMgtMvOlQh62-dzxf3eHyhgQ1KZWVLQMP0Qw2QXoGCClmoFe_PsUaepWP9_IgdZFigtL3qCoZWEY31JspH2aY-r5sy58lflSMfbbYT30XsmDWnQXHhQN96yXGMkbLr-7A1Ig_MK_FoEWN0BCxcTZBhnmTQo7JpwfwMAiiDAFwbLpaPrYtP-MuGwf-sAdWYU8n8Rxr884lyzMcpNtg7WJc5bi6PMQQIyfAoupmd4jDQCph4kOLFlHJIs6GZ62R9HgO4I9we5w5syxj3Lz06Q_HuwVXV7lOato5Iuj5P1h4dBRmweGl2Gi35QN2a-MMOHteFgz13BCY8FXDcRZ-62dQgjQ1yjFg1xalbllnxdqydDvEUuswikPV3OsBy0 "Theme sample")
+
+## List of available C4-themes
+
+Atm we have no finished C4-themes....
+
+## How to write custom theme
+
+WIP ...
+
+The sample theme C4_FirstTest [puml-theme-C4_FirstTest.puml](themes/puml-theme-C4_FirstTest.puml)  is stored in the themes folder
+
+### Following variables could be set in theme definitions too
+
+``` plantuml
+!$ELEMENT_FONT_COLOR ?= "#FFFFFF"
+!$ARROW_COLOR ?= "#666666"
+!$BOUNDARY_COLOR ?= "#444444" 
+!$BOUNDARY_BG_COLOR ?= "transparent" 
+!$LEGEND_FONT_COLOR ?= "#FFFFFF" 
+!$LEGEND_TITLE_COLOR ?= "#000000" 
+!$LEGEND_DARK_COLOR ?= "#66622E" 
+!$LEGEND_LIGHT_COLOR ?= "#khaki" 
+!$SKETCH_BG_COLOR ?= "#EEEBDC"  
+!$SKETCH_FONT_COLOR ?= "" 
+!$SKETCH_WARNING_COLOR ?= "red" 
+!$SKETCH_FONT_NAME ?= "Comic Sans MS" 
+!$LEGEND_SHADOW_TEXT ?= "shadow" 
+!$LEGEND_NO_SHADOW_TEXT ?= "no shadow" 
+!$LEGEND_NO_FONT_BG_TEXT ?= "last text and back color" 
+!$LEGEND_NO_FONT_TEXT ?= "last text color" 
+!$LEGEND_NO_BG_TEXT ?= "last back color" 
+!$LEGEND_NO_LINE_TEXT ?= "last line color" 
+!$LEGEND_ROUNDED_BOX ?= "rounded box" 
+!$LEGEND_EIGHT_SIDED ?= "eight sided" 
+!$LEGEND_DOTTED_LINE ?= "dotted" 
+!$LEGEND_DASHED_LINE ?= "dashed" 
+!$LEGEND_BOLD_LINE ?= "bold" 
+!$LEGEND_BOUNDARY ?= "boundary" 
+!$LEGEND_DASHED_BOUNDARY ?= "dashed" 
+'$LEGEND_DASHED_TRANSPARENT_BOUNDARY ?= "dashed, transparent" 
+!$LEGEND_DASHED_TRANSPARENT_BOUNDARY ?= "dashed" 
+!$SKETCH_FOOTER_WARNING ?= "Warning:" 
+!$SKETCH_FOOTER_TEXT ?= "Created for discussion, needs to be validated" 
+!$STEREOTYPE_FONT_SIZE ?= 12 
+!$TECHN_FONT_SIZE ?= 12 
+!$ROUNDED_BOX_SIZE ?= 25 
+!$EIGHT_SIDED_SIZE ?= 18 
+!$ARROW_FONT_SIZE ?= 12 
+!$LEGEND_DETAILS_SMALL_SIZE ?= 10 
+!$LEGEND_DETAILS_NORMAL_SIZE ?= 14 
+!$COMPONENT_FONT_COLOR ?= "#000000" 
+!$COMPONENT_BG_COLOR ?= "#85BBF0" 
+!$COMPONENT_BORDER_COLOR ?= "#78A8D8" 
+!$EXTERNAL_COMPONENT_FONT_COLOR ?= $COMPONENT_FONT_COLOR 
+!$EXTERNAL_COMPONENT_BG_COLOR ?= "#CCCCCC" 
+!$EXTERNAL_COMPONENT_BORDER_COLOR ?= "#BFBFBF" 
+!$CONTAINER_FONT_COLOR ?= $ELEMENT_FONT_COLOR 
+!$CONTAINER_BG_COLOR ?= "#438DD5" 
+!$CONTAINER_BORDER_COLOR ?= "#3C7FC0" 
+!$EXTERNAL_CONTAINER_FONT_COLOR ?= $ELEMENT_FONT_COLOR 
+!$EXTERNAL_CONTAINER_BG_COLOR ?= "#B3B3B3" 
+!$EXTERNAL_CONTAINER_BORDER_COLOR ?= "#A6A6A6" 
+!$PERSON_FONT_COLOR ?= $ELEMENT_FONT_COLOR 
+!$PERSON_BG_COLOR ?= "#08427B" 
+!$PERSON_BORDER_COLOR ?= "#073B6F" 
+!$EXTERNAL_PERSON_FONT_COLOR ?= $ELEMENT_FONT_COLOR 
+!$EXTERNAL_PERSON_BG_COLOR ?= "#686868" 
+!$EXTERNAL_PERSON_BORDER_COLOR ?= "#8A8A8A" 
+!$SYSTEM_FONT_COLOR ?= $ELEMENT_FONT_COLOR 
+!$SYSTEM_BG_COLOR ?= "#1168BD" 
+!$SYSTEM_BORDER_COLOR ?= "#3C7FC0" 
+!$EXTERNAL_SYSTEM_FONT_COLOR ?= $ELEMENT_FONT_COLOR 
+!$EXTERNAL_SYSTEM_BG_COLOR ?= "#999999" 
+!$EXTERNAL_SYSTEM_BORDER_COLOR ?= "#8A8A8A" 
+!$NODE_FONT_COLOR ?= "#000000" 
+!$NODE_BG_COLOR ?= "#FFFFFF" 
+!$NODE_BORDER_COLOR ?= "#A2A2A2"
+
+```
+
diff --git a/percy/TestLegendSprite.puml b/percy/TestLegendSprite.puml
index c372fdc..216fa12 100644
--- a/percy/TestLegendSprite.puml
+++ b/percy/TestLegendSprite.puml
@@ -29,7 +29,7 @@ AddContainerTag("files", $sprite="file_server", $legendText="file server contain
 
 AddContainerTag("conApp", $sprite="img:http://plantuml.com/logo3.png{scale=0.3}", $legendSprite="img:http://plantuml.com/logo3.png{scale=0.1}", $legendText="console application")
 
-UpdateElementStyle("external_system", $bgColor=$EXTERNAL_SYSTEM_BG_COLOR, $fontColor=$ELEMENT_FONT_COLOR, $borderColor=$EXTERNAL_SYSTEM_BORDER_COLOR, $sprite = "osa_server", , $legendText="external system")
+UpdateElementStyle("external_system", $bgColor=$EXTERNAL_SYSTEM_BG_COLOR, $fontColor=$EXTERNAL_SYSTEM_FONT_COLOR, $borderColor=$EXTERNAL_SYSTEM_BORDER_COLOR, $sprite = "osa_server", , $legendText="external system")
 
 AddRelTag("firewall", $textColor="$ARROW_COLOR", $lineColor="$ARROW_COLOR", $sprite="&envelope-closed", $techn="HTTPS", $legendText="firewall")
 AddRelTag("plantuml", $textColor="$ARROW_COLOR", $lineColor="$ARROW_COLOR", $sprite="img:http://plantuml.com/logo3.png{scale=0.1}", $legendText="console triggered")
diff --git a/percy/TestTagSupportsSprite.puml b/percy/TestTagSupportsSprite.puml
index fc98a07..b007130 100644
--- a/percy/TestTagSupportsSprite.puml
+++ b/percy/TestTagSupportsSprite.puml
@@ -33,7 +33,7 @@ AddContainerTag("files", $sprite="file_server", $legendText="file server contain
 
 AddContainerTag("conApp", $sprite="img:http://plantuml.com/logo3.png{scale=0.3}", $legendSprite="img:http://plantuml.com/logo3.png{scale=0.1}", $legendText="console application")
 
-UpdateElementStyle("external_system", $bgColor=$EXTERNAL_SYSTEM_BG_COLOR, $fontColor=$ELEMENT_FONT_COLOR, $borderColor=$EXTERNAL_SYSTEM_BORDER_COLOR, $sprite = "osa_server", , $legendText="external system")
+UpdateElementStyle("external_system", $bgColor=$EXTERNAL_SYSTEM_BG_COLOR, $fontColor=$EXTERNAL_SYSTEM_FONT_COLOR, $borderColor=$EXTERNAL_SYSTEM_BORDER_COLOR, $sprite = "osa_server", , $legendText="external system")
 
 AddRelTag("firewall", $textColor="$ARROW_COLOR", $lineColor="$ARROW_COLOR", $sprite="firewall,scale=0.3,color=red", $legendText="firewall")
 AddRelTag("plantuml", $textColor="$ARROW_COLOR", $lineColor="$ARROW_COLOR", $sprite="img:http://plantuml.com/logo3.png{scale=0.1}", $legendText="console triggered")
diff --git a/percy/TestTagSupportsSpriteTechn.puml b/percy/TestTagSupportsSpriteTechn.puml
index 667993d..c5a0b2d 100644
--- a/percy/TestTagSupportsSpriteTechn.puml
+++ b/percy/TestTagSupportsSpriteTechn.puml
@@ -33,7 +33,7 @@ AddContainerTag("files", $sprite="file_server", $legendText="file server contain
 
 AddContainerTag("conApp", $sprite="img:http://plantuml.com/logo3.png{scale=0.3}", $legendSprite="img:http://plantuml.com/logo3.png{scale=0.1}", $legendText="console application")
 
-UpdateElementStyle("external_system", $bgColor=$EXTERNAL_SYSTEM_BG_COLOR, $fontColor=$ELEMENT_FONT_COLOR, $borderColor=$EXTERNAL_SYSTEM_BORDER_COLOR, $sprite = "osa_server", , $legendText="external system")
+UpdateElementStyle("external_system", $bgColor=$EXTERNAL_SYSTEM_BG_COLOR, $fontColor=$EXTERNAL_SYSTEM_FONT_COLOR, $borderColor=$EXTERNAL_SYSTEM_BORDER_COLOR, $sprite = "osa_server", , $legendText="external system")
 
 AddRelTag("firewall", $textColor="$ARROW_COLOR", $lineColor="$ARROW_COLOR", $techn="HTTPS", $sprite="firewall,scale=0.3,color=red", $legendText="firewall")
 AddRelTag("plantuml", $textColor="$ARROW_COLOR", $lineColor="$ARROW_COLOR", $techn="HTTPS", $sprite="img:http://plantuml.com/logo3.png{scale=0.1}", $legendText="console triggered")
diff --git a/percy/TestThemeSupport.puml b/percy/TestThemeSupport.puml
new file mode 100644
index 0000000..22c8cca
--- /dev/null
+++ b/percy/TestThemeSupport.puml
@@ -0,0 +1,48 @@
+@startuml
+
+' convert it with additional command line argument -DRELATIVE_INCLUDE="./.." to use locally
+!if %variable_exists("RELATIVE_INCLUDE")
+  ' !theme C4_FirstTest from %get_variable_value("RELATIVE_INCLUDE")/themes
+  !theme C4_FirstTest from ./../themes
+
+  !include %get_variable_value("RELATIVE_INCLUDE")/C4_Component.puml
+!else
+  !theme C4_FirstTest from https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/themes
+
+  !include https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/C4_Component.puml
+!endif
+
+Person_Ext(customer, "Customer", "A customer of Widgets Limited.")
+
+Enterprise_Boundary(c0, "Widgets Limited") {
+    Person(csa, "Customer Service Agent", "Deals with customer enquiries.")
+
+    System(ecommerce, "E-commerce System", "Allows customers to buy widgts online via the widgets.com website.")
+
+    System(fulfilment, "Fulfilment System", "Responsible for processing and shipping of customer orders.")
+}
+
+System_Ext(taxamo, "Taxamo", "Calculates local tax (for EU B2B customers) and acts as a front-end for Braintree Payments.")
+
+System_Ext(braintree, "Braintree Payments", "Processes credit card payments on behalf of Widgets Limited.")
+
+System_Ext(post, "Jersey Post", "Calculates worldwide shipping costs for packages.")
+
+Rel_R(customer, csa, "Asks questions to", "Telephone")
+
+Rel_R(customer, ecommerce, "Places orders for widgets using")
+
+Rel(csa, ecommerce, "Looks up order information using")
+
+Rel_R(ecommerce, fulfilment, "Sends order information to")
+
+Rel_D(fulfilment, post, "Gets shipping charges from")
+
+Rel_D(ecommerce, taxamo, "Delegates credit card processing to")
+
+Rel_L(taxamo, braintree, "Uses for credit card processing")
+
+Lay_D(customer, braintree)
+
+SHOW_LEGEND()
+@enduml
diff --git a/samples/C4CoreDiagrams.md b/samples/C4CoreDiagrams.md
index 194b130..d958af2 100644
--- a/samples/C4CoreDiagrams.md
+++ b/samples/C4CoreDiagrams.md
@@ -4,6 +4,7 @@ The following samples are reproductions with C4-PlantUML from [C4 model core dia
 
 - [📄 C4-PlantUML](../README.md#c4-plantuml)
 - [📄 Layout Options](../LayoutOptions.md#layout-options)
+- [📄 Themes (WIP), Changeable Styles](#themes-wip-changeable-styles)
 - samples
   - [📄 C4 Model Diagrams](#c4-model-diagrams)
     - [Core Diagrams](#core-diagrams)
diff --git a/themes/puml-theme-C4_FirstTest.puml b/themes/puml-theme-C4_FirstTest.puml
new file mode 100644
index 0000000..4cb28e7
--- /dev/null
+++ b/themes/puml-theme-C4_FirstTest.puml
@@ -0,0 +1,54 @@
+' First test with themes (it depends on a original theme, changes colors and set $TECHN_FONT_SIZE)
+
+!theme cyborg
+
+!$ELEMENT_FONT_COLOR = $PRIMARY_TEXT
+
+!$ARROW_COLOR = $PRIMARY_LIGHT
+
+!$BOUNDARY_COLOR ?= $PRIMARY_DARK
+!$BOUNDARY_BG_COLOR ?= "transparent"
+
+!$LEGEND_FONT_COLOR ?= "#FFFFFF"
+!$LEGEND_TITLE_COLOR ?= "#000000"
+' %darken(darkkhaki,50), #khaki
+!$LEGEND_DARK_COLOR ?= "#66622E"
+!$LEGEND_LIGHT_COLOR ?= "#khaki"
+
+!$PERSON_FONT_COLOR = $INFO_TEXT
+!$PERSON_BG_COLOR = $INFO_LIGHT
+!$PERSON_BORDER_COLOR = $INFO_DARK
+
+!$EXTERNAL_PERSON_FONT_COLOR ?= $INFO_TEXT
+!$EXTERNAL_PERSON_BG_COLOR ?= $INFO_DARK
+!$EXTERNAL_PERSON_BORDER_COLOR ?= $INFO_LIGHT
+
+!$SYSTEM_FONT_COLOR ?= $SUCCESS_TEXT
+!$SYSTEM_BG_COLOR ?= $SUCCESS_LIGHT
+!$SYSTEM_BORDER_COLOR ?= $SUCCESS_DARK
+
+!$EXTERNAL_SYSTEM_FONT_COLOR ?= $SUCCESS_TEXT
+!$EXTERNAL_SYSTEM_BG_COLOR ?= $SUCCESS_DARK
+!$EXTERNAL_SYSTEM_BORDER_COLOR ?= $SUCCESS_LIGHT
+
+!$CONTAINER_FONT_COLOR ?= $WARNING_TEXT
+!$CONTAINER_BG_COLOR ?= $DANGER_LIGHT
+!$CONTAINER_BORDER_COLOR ?= $DANGER_DARK
+
+!$EXTERNAL_CONTAINER_FONT_COLOR ?= $WARNING_TEXT
+!$EXTERNAL_CONTAINER_BG_COLOR ?= $DANGER_DARK
+!$EXTERNAL_CONTAINER_BORDER_COLOR ?= $DANGER_LIGHT
+
+!$COMPONENT_FONT_COLOR ?= $PRIMARY_TEXT 
+!$COMPONENT_BG_COLOR ?= $PRIMARY_LIGHT
+!$COMPONENT_BORDER_COLOR ?= $PRIMARY_DARK
+
+!$EXTERNAL_COMPONENT_FONT_COLOR ?= $PRIMARY_TEXT 
+!$EXTERNAL_COMPONENT_BG_COLOR ?= $PRIMARY_DARK
+!$EXTERNAL_COMPONENT_BORDER_COLOR ?= $PRIMARY_LIGHT
+
+!$NODE_FONT_COLOR ?= $SECONDARY_TEXT
+!$NODE_BG_COLOR ?= $SECONDARY_LIGHT
+!$NODE_BORDER_COLOR ?= $SECONDARY_DARK
+
+!$TECHN_FONT_SIZE = 18
\ No newline at end of file