True blue: celebrities go cerulean

Whether providing a more punky take on dip-dyed lengths or used as an all-over application for cartoon-inspired colour, blue isn't a hue for shrinking violets - but as these celebs prove, there are several ways to wear it for a temporary summer shade update.

"Selena has a naturally amazing face and gorgeous hair, but I think all the strong colours through the underside of her hair cheapen the overall look. The body and flick in the hair also date it and make her look older. I would cut her hair to one length but reduce the weight by texturising it to still allow movement, without the Desperate Housewife layers."

"Kat's slick, sharp ponytail really sets off her outfit, make-up and accessories. The silhouette is chic and stylish and the added hairpiece at the base is a great example of how an ugly-looking hairband can be disguised. The use of the soft, pastel blue-silver tone looks far more elegant and sophisticated than some of the brash colours that we've seen a lot of lately, but I do think that this look is best suited to younger clients."

"I think blue can work when it's either dip-dyed or added with strategically placed streaks, but in this case I'm not overly keen. The blue sections here are not that even and one side looks quite faded out. I would like to see this same pattern done well, with her roots touched up. It's interesting though that Katy has used hair colour to make a statement after her public split from Russell Brand." 

"Fashion designers have been sending their models down the catwalk with some rather assertive shades running throughout their hair - Spring/Summer 2012 is not about to shy away from colour. One shade that is all about the impact is blue. Alice is a celebrity who embraces a trip to the hairdressers - never a shrinking violet - she has taken this trend, and made it her own. Rather than an all over application, Alice has moved the ombré look on by incorporating bright hues."