My B-day cake this year was Heart-Shaped Rainbow - I almost cried of happiness when my friends were singing to me :D
I've ALWAYS wanted rainbow hair.. but my hair is too dark so 2 years ago, I bought a rainbow hair extension on Etsy.
But lately ... (2 days ago, my bf said something like.. "you've always wanted rainbow hair, so do it!") So, maybe I will.. :) In the meantime, here are some rainbow inspirations!