Probably due to Game Freak logic, the bright pink Payapa Berry is considered red and makes Coolness increasing Pokéblocks while the vaguely beige and black Enigma Berry is considered yellow and makes Toughness increasing Pokéblocks.
This may also be due to the fact that berries are sometimes grouped according to taste, where red berries are usually spicy while green ones are usually bitter. This is probably why the Rawst Berry creates green Pokéblocks, as it is bitter, and to correspond with the other 4 basic status curing berries, the Cheri, Chesto, Pecha and Aspear berries. However, this is not always the case, as with the sweet but green Watmel Berry
Also, in the Mystery Dungeon games, the Rawst Berry is green as they are unripe and are less bitter, though I'm pretty sure berries can't "unripen".
Source: Experience, Bulbapedia's page on the Rawst Berry, and Serebii's page on Pokéblocks