Maybe he's going X Factor crazy and paying tribute to erstwhile contestant Rhydian, or maybe Mark Ronson's realised that when you've got a very boring stage presence, it's important to keep fans interested in you.

That's presumably the only reason why he would dye his hair bright blonde.

The Bang Bang producer, celebrity hookup enabler and knob-twiddler has debuted the new 'do on the cover of Black Book's reinvention issue.

He's also said of his sister Samantha's erstwhile relationship with Lindsay Lohan: “Life in LA really is one big episode of Entourage."

"If [Samantha's] happy in her relationships, then I’m psyched for her. When she’s not, I’m not.”

We're not sure how psyched Sam's going to be about Mark's hair, although it does mean he'll be able to accompany her to any gay clubnight in the world.

We think he should leave a coiff like this for Robyn and maybe Vicky Becks circa 2006.

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