Hi Jorge,
With Regards to Customize the appearance of the SymbolPalette, We have provided more custom options for SymbolPalette. we have created a simple sample to represent your requirement. Please refer to the sample from the attachment.
Sample details:
In that sample, the click made in the Button(Named as “ChangeColor”) changes the appearance of the SymbolPalette.
For more details about Customizing option for Symbol Palette, Please refer to the Online Help Documentation.
Link:
http://help.syncfusion.com/resources/Content/ug_101/user%20interface/silverlight/diagram/documents/customizingthesymbolpalette.htm Please let us know if you have any concerns.
Regards,
Ramya
CustomizetheColorofSymbolPalette_ff955204.zip