Katy Perry celebrated her 25th birthday with a Willy Wonka-styled event on Saturday.

The “Hot N Cold” singer held the bash at The Sunset Beach nightspot in Los Angeles and guests - who had been told to wear white - were left covered head-to-toe in paint. “They got a little crazy with the paint. I wasn’t expecting it but everyone got painted - even Taylor Swift!” an attendee said.

The party - which was inspired by Wonka’s workshop from Roald Dahl’s Charlie and the Chocolate Factory - had Oompah Loompahs running around and a huge variety of candy and chocolate.

Guests say the birthday girl and boyfriend Russell Brand couldn’t keep their hands off each other.

“They were totally loved up! Katy was having a ball and Russell was catering to her every whim. At one point he was down on his knees bowing and offering her a huge swirly lollipop. She grabbed it from his hands and pretended to knight him with it,” one reveler said.

Celebrity blogger Perez Hilton was among the guests and insists Katy’s hospitality didn’t disappoint. “Dinner included lots of yumminess, especially some deelish yellow and green mashed potatoes - and there were so many sweets downstairs for dessert that we’re surprised we didn’t go into a food coma,” Hilton wrote.