WeltallZero
Smash Cadet
After reading that blue pikmin didn't drown while the rest did, I went and made some testing. Here's what I found.
1) Most testing was done with Olimar's fsmash, as it throws pikmin and it's easy to spam it with one hand while controlling the other character. Remember that pikmin aren't vulnerable while following Olimar, only when they're on their own after being thrown.
2) Blue pikmin do survive in water, while the rest die almost instantly.
3) Blue pikmin are also immune to water attacks. Tested with Squirtle, whick killed most pikmin in one hit with his up smash while it didn't even affect (went through) blue pikmin. Interestingly, I didn't manage to kill purple pikmin with this move, but at least they were knocked upwards.
4) Yellow pikmin are indeed immune to electricity-based attacks. Pikachu's B kills most pikmin in two hits (whites in one, purples take more but do die), but again ill go through yellows.
5) You're probably not going to be surprised by this at this point, but Bowser's breath went through the reds without affecting them. On the others it did more knockback than damage, taking two hits to kill a white and five to off a blue. This incidentally confirms that pikmin have their own individual HP which persist through getting back into the queue.
6) I couldn't think of poison-elemental attacks to test white pikmin. I tried the Wario Waft ^^ but it did kill the white pikmin (in one hit as per usual with whites).
1) Most testing was done with Olimar's fsmash, as it throws pikmin and it's easy to spam it with one hand while controlling the other character. Remember that pikmin aren't vulnerable while following Olimar, only when they're on their own after being thrown.
2) Blue pikmin do survive in water, while the rest die almost instantly.
3) Blue pikmin are also immune to water attacks. Tested with Squirtle, whick killed most pikmin in one hit with his up smash while it didn't even affect (went through) blue pikmin. Interestingly, I didn't manage to kill purple pikmin with this move, but at least they were knocked upwards.
4) Yellow pikmin are indeed immune to electricity-based attacks. Pikachu's B kills most pikmin in two hits (whites in one, purples take more but do die), but again ill go through yellows.
5) You're probably not going to be surprised by this at this point, but Bowser's breath went through the reds without affecting them. On the others it did more knockback than damage, taking two hits to kill a white and five to off a blue. This incidentally confirms that pikmin have their own individual HP which persist through getting back into the queue.
6) I couldn't think of poison-elemental attacks to test white pikmin. I tried the Wario Waft ^^ but it did kill the white pikmin (in one hit as per usual with whites).