Katy Perry debuted with blue hair at her first public appearance on Friday after her split with Russel Brand in December 2011.

The electric blue hair colour added to her stunning looks in a short black cocktail dress at the GiveLove charity event held in Las Vegas to raise support for earth quake-ravaged Haiti.

Katy Perry is known for switching her hair colours and has showcased her coloured hairdos at many red carpet appearances throughout last year.

Check out the "I Kissed A Girl" singer in her varied hairstyles over the past one year: