For his Up+B it would be awesome if all the pikmin he had grabbed eachother to make a rope for tether recovering, and the more pikmin the better recovery, that would be pretty sick.
Also, about this colour thing. If they were to incorporate the fact that some Pikmin are immune to characters, I don't think it would be fair if some characters had no disadvantages to certain Pikmin.
So let's all make a list of each character with 1 move that could be immune to a single Pikmin for every character currently announced.
Mario - Red is immune to Mario's neutral B.
Link - Red is immune to Link's bombs, or better yet, Yellow can catch Link's bombs.
Kirby - If Kirby inhaled White Pikmin he would suffer damage.
Pikachu - Yellow Pikmin are immune to all Pikachu's electric attacks.
Fox - Red are immune to Fox's Firefox, or Purple Pikmin can be used as a shield towards Fox's pansy blaster.
Samus - Red immune to missles and bombs.
Zelda - Red immune to Din's Fire.
Bowser - Red immune to fire.
Donkey Kong - Can't pick up Olimar? Think of it like this, DK trys to pick up Olimar but a Purple pikmin weighs him down.
Yoshi - Hurts to eat White Pikmin
Peach - Red pikmin can't be hurt by butt blast?
Ice Climbers - Blue Pikmin arn't really immune to ice... but I guess make it so they are.
Pit - No idea.
Wario - Hurts to eat white Pikmin.
Zamus - No idea.
Ike - Red are immune to explosion.
Squirtle - Blue are immune to all of Squirtles water based attacks.
Ivysaur - Vinewhip can't grap Purple Pikmin.
Charizard - Red are immune to fire.
Diddy Kong - Yellow can pick up bananas?
Metaknight - No idea.
Snake - Red are immune to explosives.
Lucas - Blues immune to PK Freeze? Reds immune to PK fire, Yellow immune to PK thunder.
Sonic - If a purple pikmin lands on Sonic's spring, the spring breaks.
King Dedede - Red's immune to jet hammer? Can't inhale white pikmin without suffering damage.
Captain Olimar - Pikmin are futile towards Olimar.
As you can see, Red Pikmin dominate. I can't remember, but I don't think they were immune to explosives, so I guess you could remove that, but by doing that, if a character has no disadvantage towards Pikmin, would that be fair? I don't think it would considering Yellow dominate Pikachu.