Use modulo, not bitwise AND. My fault once again, whoops.

The point here is ColorOpposite(MAXSKINCOLORS) would have given an actual result of its own since MAXSKINCOLORS & MAXSKINCOLORS is still MAXSKINCOLORS. This shouldn't happen though, as both Color_Opposite[MAXSKINCOLORS*2] and Color_Opposite[MAXSKINCOLOR*2+1] aren't defined.