Sienna Miller's rose gold meets peach emoji tint basically broke the internet.
A black dip dye? Drew Barrymore makes it look effortless.
Remember that time Rachel McAdams added pink highlights? We kind of try not to as well...
Proving turquoise isn't always hard to pull off, Lady Gaga's super blunt bob was epic.
Queen of pastel hair Katy Perry goes for a bubblegum pink cartoon vibe.
Jaime King working an ombre 'do in blue and aqua.
Former ELLE cover star Rita Ora with a frosted pink bob.
Miley Cyrus working grey/blue hair at the Met Gala in New York, May 2015.
Big Bang Theory star Kaley Cuoco debuted not only pink hair but pink eyebrows too.
Georgia May Jagger was the latest celebrity to join the rainbow hair club, courtesy of BLEACH London, August 2015.
Ellie Goulding debuted new yellow locks at the MTV EMA's in Italy, October 2015.
Nicole Richie is just too cute. A sleek flicked bob in a muted sky blue looks chic without straying into twee territory.
Yet another colour reinvention for Katy Perry and we're loving her tousled lavender waves.
Rainbow hair doesn't always have to mean paint box brights. Work a grungier shade by adding grey undertones to a pastel colour like Hilary Duff.
Sleek, chic and red carpet ready, Nicole Richie's blush coloured hair is firmly on our beauty to-do list.
Working her signature woodland elf meets super cool musician look, we're loving Grimes' pastel pink and black hair.