While many of us have unlocked the other colors by fully playing a character in story mode, or winning 25 times with them, that elusive 10th palette was always out of our reach. Armed with just some scant ‘hints’ from Mike_Z Ravidrath the internet set off to find the ‘old school’ code necessary to unlock the colors.
Now we’ve got it! Thanks to sideburns on the SRK forum!
Both codes require you to be at the ‘local’ versus screen while selecting player side / control and being player one.
Xbox: Down, RB, Up, LB, Y, B, Start
Playstation 3: Down, R1, Up, L1, Square X
Enjoy your 10th palette everyone!