How do you change the colors of conflict highlighting when resolving git conflicts.

I have adjusted the color of my error highlighting, but despite hunting and trying several other settings I can't seem to find the one that effects error conflict highlighting. This is important too me as I currently find it difficult to tell the difference between non-highlighted code, code which is highlighted as a conflict, and the lighter colored difference highlighting.

Anyone know where it is at? 

Version: 2017.3

platform: macOS Sierra