You want to use colors.
But first, you must have a little star next to your name.
What does that mean?
You have to be a sponsor.
If you are not a sponsor, then you cannot use colors, sorry.

1

There are two ways to do colors.
Either you can use the drop down menu, when it is present,

OR, you can type out the command.
[color=red]This Text Will Show Up Red[/color]

2

You can use colored text anywhere you can type.

3

Here is a list of all the colors you can use after the [color= tag

No, really, that's all there is to it...
Go play with some colors!