Haha, Ive got a albino Budgie who gets a multi colored face after she get s a drink or takes a dunk in the water dish and then goes and climbs all over the playgym
then earlier today we were in with the birds and I saw Crash and violet my normal lookin budgies who have white faces -- There faces were Yellow, I couldn't fiqure out why for a few mins
we thought perhaps they were matureing and were actually yellow face violets
and boy did i feel dumb when I realized what it was, I saw bob (dominate blue pied opaline, with a yellow tinge to his face, and tweety who's face is white he/she is a dom. blue pied also had a tinge of yellow) now i knew there was no way 4 of my white faced budgies were turning into yellow faces
Then i remembered my boyfriend took the pinapple shapped cuttlebone/ mineral block thing and grounded it up and we've been adding it to thier food because none of them seemed to use it like they did the cuttlebones, and we're out of cuttlebones at the moment
then it dawned on me That's why their faces ARE YELLOW

the pinapple is Yellow and we turned it into a powder and sprinkle it on thier food and mix it in
so there was that mystery solved