I realise this is a simple thing that many people know, but then again, there's A LOT of people that are not aware of how to do this.

Excuse my horrible circle drawing skills. Lol.

Step #1: Click the icon as circled below.



Step #2: Type in the actual name of the color you would like to use after the "="

Step #3: In the middle, between the two brackets separating "[ color=red ]" and "[ /color ]" is where you type what you would like to say in the shout box as shown below.

There are normally not spaces in the color command thing, I had to put them there so it would not try and color my words.



Congratz, you now know how to use color in the shoutbox!

I'm not completely sure of what colors work. Play around with it and see what ones work! :3

 

Looks like there were 2 threads made before this that show how to do this. Probably should have checked first; but whatever, some users may not have seen them. :p