Speaking to Digital Spy at the Twilight: Breaking Dawn premiere, pink-haired Lily joked she would compliment the US popstar because of their contrasting hair colours.
"She's got cream blonde hair now. It would be like a vice versa," said Lily.
Teasing details about this weekend's Movies theme, she added: "It's going to be fun. I'm going to get everyone up off their seats!"
Lily also joined calls to stop Louis Walsh leaving The X Factor at the end of the current series.
"Don't go, Louis! Please stay," she shouted.
Additional reporting by Tom Mansell
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Move through our Breaking Dawn UK premiere gallery below: