Holly rose to fame with a shocking red barnet then, more recently, opted for an ombre purple and mauve style.
But clearly she felt it was time for a change, as the Geordie lass has now switched up her style with something even brighter!
Rumour has it, Holly chose to unveil her new Royal blue locks in time for Prince George's Christening, which took place at St. James's Palace yesterday (23 October).
Holly has now changed her Twitter profile picture and jokingly compared herself to Simpsons character Marge.
She tweeted: "What's everyone's opinion on the new BLUE hair??? #Marjjjjj"
Earlier this month, we told how Holly dyes her hair at home herself, using her own range with Manic Panic.
And it seems she is the master behind this new look too! Holly also told fans: "My new hair colour is ROCKABILLY BLUE from my range."
What do you think of Holly's hair? Tell us below, as the best comment from across the website each week wins £50!