The color code is basically this:
<color=R,G,B>
R is percentage of red.
G is percentage of green.
B is percentage of blue.
A percent is changed to decimal from 0 to 1.
For underline, I use
TEXT in my RMS scripts and scenario designs.
Icons are done by:
<icon=(#)(path)>
# is the pixel size.
path is the path of the image you want to use.
For example, Fort Wars uses:
<icon=(20)(ui\hp_cp\hp_cp_rec_gold)>
Which gives the gold icon.
These are all the same as if you were designing a scenario or RMS.
Elpea even discovered how to use different fonts using:
<font=Fontname>