Color codes mice on GWH maps according to decorations & cheese
< Opinie na MouseHunt - GWH Map Color Coder
Try installing v1.2 - if that doesn't work you might want to try Tampermonkey instead (I assume you're using Greasemonkey since other users have reported the same problem)
Error
Ignoring @match pattern .mousehuntgame.com/ because: Error: @match: Could not parse the pattern: .mousehuntgame.com/