Hi Andreas, thx for letting me not alone
Sry, Never heard of group layer colors and how to set it up. I couldn't find anything about it except that in Blender 2.79 there used to be something like group object. In the render panels I can´t find a group layer color checkbox. I this a secret feature that I missed or more worse a standard feature that I missed all the years?
Thx for your affords ...