You don't. What you change is the the text's color:

FONT* arial_font = "Arial#20b";

TEXT* mytext =
{
flags = SHOW;
font = arial_font;
string("this will be red");
red = 255;
green = 60;
blue = 60;
}

Correct me if I'm wrong.

~"I never let school interfere with my education"~
-Mark Twain