AFAIK it's better to create a FONT* first and use it in the digits that to define the font within the digits definition. I even heard that it wouldn't work like this (but that could have changed), but even if it does it's not to be recommended at least if you want to use the same font at many digints or TEXT*s.
Code:
FONT* my_font = "Arial#24bi";
PANEL* my_panel =
{
digits (50, 100,2, my_font, 1, my_text);
red = 0;
green = 0;// black rgb is 0,0,0.
blue = 0;
flags = VISIBLE;
}
And this way you just have to edit the font definition if you want to change many digits that use the same font.