Like I said before it's not that hard to come up with a simple solution.
Every controller port corresponds to a color.
P1 = Red
P2 = Blue
P3 = Yellow
P4 = Green
Whatever palette swap you choose doesn't matter if you pick this stage. The game will override your color choice and slap on your controller ports color to your character's accent colors. Remember the game already does this when you enter your name for the triangle icon above your head. And when you don't enter a name the game has your player number in the same corresponding controller port color floating above your head.
So if you played a match with four DK's then you'd have a red tie, a blue tie, a yellow tie, and a green tie.
edit: And the game would do exactly what it does if you pick the same two characters for a team battle.