The cost to get rainbow hair varies depending on which salon you visit, your hair's current color and condition, the length of your hair, and whether you want an all-over rainbow or just highlights. A temporary DIY rainbow look can be achieved with hair chalk or wash-out dyes, which retail for less than $20. On the other hand, if you have naturally very dark, long hair and want to go completely rainbow, the colorist will need to bleach and tone your hair to a light blonde first. This process can take several sessions and cost $300 or more. However, if you have short, naturally blonde hair – or just want rainbow tips or a rainbow fringe – the price will be much cheaper.