<span style="color:#ff8800"><b>TEXT</b></span> = TEXT
Weasyl accepts HTML format

Or if you're use Postybirb, while you are putting in your text, switch from "Rich Text" to "Simple" and just go ham on [color=limegreen]TEXT[/color] and then switch back to rich text and it will be all colored and coded in your next post so you know what the html code is.