I noticed these normal decals from an Overwatch reference that somehow also allow diffuse information with a mask: From what I've experimented with, it doesn't seem possible in UE4? I was hoping someone knew if there was an actual solution or if this is just a limitation of the engine: Currently, it's a waste of polys but…
Is this what you're looking for? I think from your post this is what you mean to do Using a mask I lerped it between the decal base color and colored the mask with a color and multiply node. You could make a mask for what sections you want to have a different color and then have it only applied to those area's. For…