Additive primary colors for multiple overlapping geometries

I am trying to visualize the collision-outline for multiple obstacles from 3 different IsoVist sampling locations. Each collision outline get separate color in Red Green and Blue. I have tried a lot of maths attempts to merge the overlapping surfaces and do “additive mixing” of the colors, getting colors White, Yellow, Cyan and Magenta where the surfaces overlap (and in addition cull the duplicate surfaces)IsoVist RGB (167.5 KB) , but fail to succeed.

The principle of additive primary colors works perfectly on simple flat mesh, but I fail to get the proper mapping of the list to make this work properly when using multiple obstacles breps and it’s component untrimmed surface

GH (source and simplified internalized data) and Image attached.
GH version: still on 0.9.0076 and Rhino 5