Thanks for all the info! I'll look into the exponential brightness math, because I just can't see it with my eyes...

The AA colors on the Blue and the "violett" should be a little brighter. Even the Red one could be a weee bit brighter (it's not always as simple as just picking the average color; perceptual brightness is exponential in nature, therefore an average of two RGB-values may sometimes appear darker than desired, this will in turn affect the (related) phenomena of clusters, banding and AA)

Thanks a lot! Glad to know I'm not just fooling myself. =)

yes. Your AA is much better :)