Katy Perry and Britney Spears were among the stars who turned out to greet everyone's favourite little blue men (and women) at the premiere of The Smurfs 2 in LA.

Katy, who reprises her voice role as a Smurfette in the film, wore a blue Tadashi Shojidress and Pedro Garcia heels.

In fact, blue was - obviously - the colour of the night, as Britney almost clashed with Katy in an electric blue figure-hugging number.

The singer made it a family affair, and was accompanied down the red carpet by her sons Sean, seven and six-year-old Jayden James. Their mum’s new single Ooh La La features in the film.

Katy also kept the evening in the family by bringing along her grandmother for company.

Also at the premiere was co-star Christina Ricci, who wore a turquoise blue knee-length dress.