When rainbow fairies are little they hatch from rainbow eggs with coloured hair. Some have green hair, some pink, some purple, and some blue. Once upon a time Sparkle the Rainbow Fairy had blue hair. However, when rainbow fairies get bigger and turn seven, their baby hair falls out (like the yellow feathers do on baby chickens) and they get their grown-up hair which is brown, black, red or blonde. When Sparkle turned seven, roughly a few years ago, she lost her blue hair.