Hi! With a ux:Class defined as:
<Panel ux:Class="TestButton" ux:Name="self">
<Brush ux:Property="Fill" />
<Rectangle ux:Name="fillColor" Layer="Background" Fill="{Property self.Fill}" />
<WhilePressed>
<Change fillColor.Fill="{Property self.Fill}" />
</WhilePressed>
</Panel>
It fails to compile with There is nothing named '{Property self.Fill}' in this scope, and no global resources with that alias.
In the chat skezo found a fix in changing to Change to: <Change Target="fillColor.Fill" Value="{Property self.Fill}" />