quick question

yo on some peoples sigs i have seen that they have changed the colour of there text can somebody tell me how you do that plz

[ COLORE ] "color code" [ =COLORE ] "text" [ /COLORE ]
(of corse with out the spaces)
Color Codes
F00000 = red
00FF00 = green
0000FF = blue
00FFFF = light blue
FFFF00 = yellow

The code for red is "FF0000".

The code is a six-character "word", which chan be divided into three pairs. Each pair indicates the color's levels of Red, Green and Blue respectively, from 0 to 255. Each value should be transformed into hex format, and so the values to put in the code go from 00 to FF.