That's an interesting view, I never thought about it, but it could make sense. The Green and Yellow likely guide Accepted who are gifted with the right weaves to their Ajahs, while Brown, White, and Gray probably look for ones with the right aptitudes.

I think though that Tower politics plays some role in Ajah selection as well, probably most strongly with Red and Blue, since neither Ajah really needs to specialize in anything particular. Blue perhaps is more selective of the girls they guide to their faction, so they're one of the smallest factions. Red OTOH probably tries to aggressively get girls who don't show any particular aptitude for the other Ajahs, and they do seem to feel that they're the most important part of the WT as well. Red seems to be the most conservative Tower faction while Blue the most liberal, so it's not really surprising the two don't like each other at all. That makes Red a very good fit for Elaida, since she seems to have very conservative views about the AS and their place in the world, evidenced by her desire to restore the former influence the AS had on the Westlands.