Here are my Pikmin 4 ideas, hope you enjoy my thinkings of what the new game will have to offer.
New Pikmin Colors: this is a bit crazy but I think the new game will have at least 7 new Pikmin containing 7 of these 9,
Lime Green: resistant to acid which is farther down the list of things (hey, maybe the acid is from that Duracell battery from Pikmin 2)
Green: has a tail that can be used as a weapon, and can be spun around to hover for a short time.
Thorned/Dark Green: I have a picture that explains it all, and it is here: http://i19.servimg.com/u/f19/19/14/74/17/image28.jpg
Cyan: Freezes enemy when eaten, sort of like whites in a way but a different outcome, freezes water that is walked over for a short time so other Pikmin can make it over.
Glowing/Light Blue: has a glow cap on its head instead of a flower, goes from a Leaf to a Small mushroom to a big mushroom (starting one being leaf for merchandise purposes) it will light up a cave and becomes weaker outside of dark areas, and like Purples and Whites they don't have an onion
Orange: explosive resistant, only Pikmin that can carry bomb rocks because yellows have their own type now.
Gold: picture says it all, but instead of Orange it is Gold colored http://i19.servimg.com/u/f19/19/14/74/17/image29.jpg
Silver: infects bulborbs and when they die that drop spotty pellets which when brought to any onion sprout bulbmin
Brown: can burrow underground at certain areas to reach new places
Story: soon after Alph, Brittany, and Charlie go to Hocotate to drop off Olimar, reports of a stowaway on the SS Drake start going across the universe, causing Alf, Brittany, Charlie, and Olimar to come back to PNF 404, but a month later they don't come back so 3 new unconnected heroes go to find them and the stowaway, we then go down to PNF 404 and find out that the stowaway was Character D! (Who ISNT the SS Drake even though everyone thinks that) Who now has 2 Pikmin types on his grasp, soon the other 3 arrive and each get 2 Pikmin types on their landing, soon they all get another type and then another, but then the Rock Pikmin is needed to free Alph, Brittany, Charlie, and Olimar, in which there is a cutscenes of the heroes chasing down a rock Pikmin before realizing the other heroes sent to find A, B, C, and O even exist before teaming up with the other heroes, and combining their onions into one, then using rock Pikmin they break through the crystals and see Louie controlling a new boss, the Fire Wraith, after the boss is defeated the game is over, but not before seeing a little cutscene where the final 2 Pikmin types which was in my list and not available in the main game are unlocked and are usable, but Louie is left on an abandoned planet where he can't make another annoying wraith boss, this would also be the last installment of the Pikmin series.
New Game Mechanics,
Acid: mentioned earlier, Lime Green Pikmin are resistant to it, captains suit has to be upgraded to be resistant to it, but even one being upgraded doesn't benefit all captains before all 4 join eachother,
Misc:
Pikmin count limit is raised to 400 but each captain can have 100 Pikmin out at a time until all the other captains join eachother in which the counter limit is at 500
So those are my ideas! Hope you enjoyed them.