Me and a Discord friend were talking about how the Ghosts would play in Smash.
They'd function similar to a mix of Shulk and PKMN Trainer - basically imagine if you could swap between Mario and Doc mid-match, they change stats, moves don't change animation-wise or general concept-wise but do have different functionality.
Blinky (red) would the powerhouse by process of elimination, Pinky is the speedster given her ambush tactic in the original Pac-Man, Inky (blue) is the all-arounder given how his AI shifts between the other ghosts' AI, while Clyde (orange) is the heaviest with the biggest shield given his habit of running away from Pac-Man
They'd have a long laggy animation for switching (they turn into TURN-TO-BLUE, then become the next ghost) - when they're in TURN-TO-BLUE form they're super vulnerable, which makes them launch far if hit (I'm not sure yet if that's in the "broken Jigglypuff shield" way or "hit by a golden hammer" way)
Given that colours are the only real way of identifying the ghosts, they'd be the same colours for all alts.
(Even Wario and Waluigi)