Think pink! The unlikely hair dye hue that's become one of Hollywood's hottest trends

When Katy Perry dyed her hair pink, it didn't come as that much of a shock to fans.

The Teenage Dream singer has been known to change the colour of her locks almost as often as her outfits.

But since then, actresses Sienna Miller, Kate Bosworth and Glee star Dianna Agron have followed in Katy's footsteps.

    
Katy Perry, Sienna Miller and Dianna Agron have all gone for different variations of pink hair

And on last week's make-over edition of Britain and Ireland's Next Top Model, Anastasija Bogatirjova, 19, was forced to go from blonde to a pale shade of pink.

From dip-dyed to candy floss, it seems pink has become something of a trend in hair color.

Pioneered by 'Frenchy' in Grease, who accidentally tinted her hair during a beauty course, pink hair has always been a theatrical accessory rather than a fashion trend.

But in the past Lily Allen, Kelly Osbourne and of course, singer Pink, have turned to the rose-tinted bottle.

The shade can be surprisingly flattering and for celebrities who are trying to make their mark - an individual statement.

But taking the pastel plunge doesn’t have to be so drastic.

Dip dying and under colouring techniques can be used to inject a colour flashes in to the hair that are less high-maintenance. 

A pastel rinse can add a really high fashion feel to light blonde hair and create a slightly more edgy tone.

Francesco Fontana from Toni & Guy said: 'Pink is certainly a strong colour statement. 

'Choosing such an unnatural tone injects a really playful vibe into any style and offers the opportunity to totally transform your look for a real style statement. 

'If your natural shade is darker than blonde, hair will need to be pre-lightened which needs to be carried out by a professional to ensure hair stays in optimum condition but as with any un natural colour choice, be prepared for some high attendance and regular visits to the salon for a coloured toner. 

'As with any colour choice – suitability is key and choosing the right pink tone for your skin is vital – from warmer reddish tones to a more orange based pink – working with your colourist to find your perfect pink is the key to success.'

    
Singer Pink, Kelly Osbourne, pictured in 2007, and Lily Allen, in 2008, have all sported pink hair