Use a common anode led

[Hercules187]

hey all on my snes i have a spare blue led input which would be perfect for blueretro problem is its common anode so the led output pin wouldn't work, I feel the use of a transistor would be a bit of a hack how difficult would it be to switch the code over to support common anode? I have been trying to get my head round led.c but if anybody could give me any pointers that would be great.

Thanks

Steve