KATIE HOLMES is sexing up her silver-screen image to put herself back on the movie map. And she’s hoping to land a red-hot role in the film version of “50 Shades of Grey”!

Sources say that Katie, 34, plans on going platinum blonde for the role of Elena Lin­coln, kinky billionaire and main character Chris­tian Grey’s longtime sex and business partner.

The “Elena” character is known in the best-selling book as a Mrs. Robinson-type who schools Christian in the dark, deviant world of bondage and sado­masochism.

The former Mrs. Tom Cruise has been keep­ing busy since her Broadway play “Dead Ac­counts” closed in January, just two months af­ter it opened.

She had a role this past spring opposite Luke Kirby in the film “Mania Days.” And she’s been in South Africa recently shooting the ensemble  flick “The Giver” with Meryl Streep and Taylor Swift.

But none of those roles have given her the push she feels she needs to make it to the top of Hollywood’s A-list.

“She’s looking at this as the role of a lifetime for her,” said a pal. “It will shock a lot of people, but she thinks Hollywood will sit up and take notice.”

Katie has been putting in more hours at the gym to “tone her­self up for the part,” says the friend. And while she’s younger than the character in the book – who’s described as be­ing in her late 30s or early 40s – and not a natural blonde, Katie is convinced she’s the right woman for the role.

“She knows she has to reinvent herself,” said the pal.

When “Sons of Anarchy” actor Char­lie Hunnam was originally cast as Christian, Katie as­sumed she wouldn’t get the role of “Ele­na” because they’d had sex scenes to­gether in the 2002 film “Abandon.” Katie didn’t think producers would pair them again.

But now that Charlie’s out and Irish actor Jamie Dornan is in, Katie is determined to win over the film’s execs.

It will also make ex-hubby Cruise fume, say sources.