Please follow our submission template and guidelines and make a complete, valid bug report, with required info, precise description of the issue, precise steps to reproduce it, small and simple .blend and/or other files to do so if needed, etc.

A guideline for making a good bug report can be found here: https://wiki.blender.org/wiki/Process/Bug_Reports

• are you talking about object material viewport colors?
• or viewport background colors?
• (both work fine here)

Marking as "Incomplete" until the requested information/data is provided.