Namer: Syntax Preview

Enter or names

^1 - RED
^2 - GREEN
^3 - YELLOW
^4 - BLUE
^5 - CYAN
^6 - PINK
^7 - WHITE
^8 - DEFAULT MAP COLOR
^9 - GREY OR DEFAULT MAP COLOR
^0 - BLACK
^8 changes color depending what level you are on.
American maps = Dark Green
Russian maps  = Dark Red / Maroon
British maps  = Dark Blue

Greasemonkey User Script
You can also enable name replacement in Firefox using Greasmonkey and the following user script:

Install: Steam Community (re)Namer