Not sure if it's the preferred way or not, but I did this in my symbol and it works fine:(I realize the context is a bit different, in that I did inside of a MarkerSymbol instead)
<Ellipse
Fill="{Binding Attributes,
Converter={StaticResource DictionaryConverter},
ConverterParameter=EllipseFill,
Mode=OneWay}"
Height="10"
HorizontalAlignment="Left"
Margin="-5,-5,0,0"
VerticalAlignment="Top"
Width="10" />
The EllipseFill value comes from the graphic's attribute collection.*** EDIT ****Looking over the blogs and changes for 2.0, looks like the converter is no longer needed.An updated way might be like this:
<Ellipse
Fill="{Binding Attributes[EllipseFill], Mode=OneWay}"
Height="10"
HorizontalAlignment="Left"
Margin="-5,-5,0,0"
VerticalAlignment="Top"
Width="10" />