I've said quite a few times that blue gets the short end of the stick in a lot of things. Maybe not the shortest end, but a short end. You know where blue gets off like a bandit though? Alt dungeons.
Probably the most dangerous enemy in alts is probably Red Cap, since alts love to spam him on like every other last floor and his skill delay plus his gravity is an extremely potent combo. Blue is super effective against him, so it's easier for it to one-shot him and avoid the gravity. And meanwhile the blue variant on Red Cap, Kappa, isn't particularly dangerous (especially now that his preemptive is nerfed) and actually feed you tons and tons of ammo. The green member of this series, Furi, is the least dangerous of any of them so even though it takes blue a while to kill her she can't really do that much.
Meanwhile, farming alts with green seems like it would be pretty irritating. Being resisted by Red Cap might lead to some random accidental losses, and being super effective against Kappa isn't that useful since it still slows you down with a preemptive and beyond that isn't that dangerous. Cath Palug is a problem for everyone, sure, but beyond that blue has a big leg up in current alts. Even white, a color super effective against the dangerous Cath Palug and not resisted by anyone, doesn't get the constant flow of ammo from Kappa and is instead slowed down by it.
