? tab(-10, AG_ATTRSUB);"1,2,"; FG'R;","; FG'G;","; FG'B;","; BG'R;","; BG'G; ","; BG'B; chr(127);

AG_ATTRSUB (68) allows for changing the underline attribute to an arbitrary fg/bg color combination. It is useful for slight aesthetic improvement to legacy text-mode programs which use underline, since underline has a rather old-fashioned look.

where FG'R, FG'G, FG'B are the RGB values (0-255) for the foreground color, and BG'R, BG'G, BG'B are the RGB values (0-255) for the background color.