I managed to get the color purple on Forte's facial marks, but only worked for the Armor Mode.
I think Forte has 2 sets of palettes because the flaps on his helmet colored orange on Normal Mode and purple on Armor Mode, and there's no purple on Normal, which made the facial mark on Normal color orange.
Try the snes pallete utility
I tried that utility, but it seems pretty hard for me to understand on how to use it, and there are other requirements/programs needed to use it fully. I don't feel like installing extra programs just to make that thing work. Thanks anyway.