/help $cnick
In specific, $cnick($nick).color
echo -a $+ $cnick($nick).color $+ $nick is the color in the nick list.
Note that you may want to zero-pad that number if you're going to put the nick next to the color using $+... otherwise, if the nick starts with a number and the color code is 0-9, it will mess up your colors/nick.
To zero-pad it, do this:
$base($cnick($nick).color,10,10,2)
To see what that does, try:
//echo -a $base(1,10,10,2)
//echo -a $base(10,10,10,2)
As you can see, it makes the number 2 digits. Very useful for color codes.