Colour in worldspawn messages work just the same as colour in messages/funnames in paintball.
You could set your name to a specific coloured word, close paintball and re-open, then search your config.cfg file for "menu_tempname"
For example, mine is seta menu_tempname "ˆ0[ˆ9xˆ0ˆO^ˆ95ˆ0]ˆ9JMR'"
Input "ˆ0[ˆ9xˆ0ˆO^ˆ95ˆ0]ˆ9JMR'" into the message and you'll notice it works just the same.