I feel that the Pikmin are all one loosely related species, with a broad family of colors. The Pikmin are the youngest stage of life, and possibly at some point plant themselves and grow into a candy pop, or the candy pop is also planted by the onion.
As for onions, I think that when candy pop buds grow up, possibly by pollination, they produce an onion of their corresponding color. On a slightly unrelated note, do you think there are more than one of every color of onion? You only ever see one color, and so I wondered if they have some sort of natural thing that makes only one Onion of each color...
--Bluesly 21:33, December 3, 2009 (UTC)Bluesly