There's a rainbow in my head

Pastel, rainbow, unicorn, "my little pony" hair.. What ever you want to call this, this is delicious.

Definitely not a new trend now. It has been seen in editorials, and on the runway,.... but this has been in the back of my thoughts for a while now, and finally I have some time to trawl through some images.
Hmm, very tempting.