Even if the default color works, I still think there is an issue somewhere here that should be addressed.
To me it looks like the colorized user and user instances doesn’t work. If you select them in options they will sometimes be unreadable, which is an effect of recent changes to how they are displayed and their options.
Some proposals how to solve it:
Change background color
Only display the icon if colors are set
Let OP/mod colors take precedence and override the default color with them
I had the same issue as OP.
Even if the default color works, I still think there is an issue somewhere here that should be addressed.
To me it looks like the colorized user and user instances doesn’t work. If you select them in options they will sometimes be unreadable, which is an effect of recent changes to how they are displayed and their options.
Some proposals how to solve it: