If I assign a layer to a subassembly it will not change the color to that layer in drawing view. It works fine if I change layer per part level even for subassembly parts. This is very time consuming if the subassembly contains multiple parts. If I export the drawing as a dwg drawing the layer function works as intended. This use to work for me a couple of years ago but I can't remember if I have made any changes in my settings or hardware that affected it. 

I'm using Solidworks 2017 SP4.1