Though celebrities aplenty are set to bring their sense of style to NBC’s “Fashion Star,” the true tailors of the unscripted series are toiling behind the scenes.

Nicole Richie and John Varvatos were just the latest names added Thursday to the roster of mentors on the Peacock’s midseason skein, which already includes Jessica Simpson. But the star wattage is coming together under the watchful eye of 5×5 Media, the production company that just renewed its deal with Electus, the IAC-backed studio that put “Fashion” together.

The three principals of 5×5 know what it’s like to operate under the shadow of even bigger names behind the camera, too. They’ve all produced some of reality TV’s biggest franchises, with Rick Ringbakk backing Bertram von Munster on “The Amazing Race”; Craig Armstrong supporting Mark Burnett on “Survivor”; and Tod Mesirow behind Thom Beers on “Monster Garage.”

Tired of the work-for-hire life and craving an ownership stake in their work, they banded together and pacted with Electus last year. “We’ve managed to make billions for other people as accomplished showrunners,” Armstrong said. “We felt it was time to do our own thing.”

With a series for Spike TV, “Car Boss,” on tap and several more projects in development, 5×5 has become the go-to firm for Electus CEO Ben Silverman, who sees the trio’s collective varied experience as a real plus. “Most production companies have a specialty niche, but 5×5 has incredible diversity,” he said. “Their alternative production and creative ability is superlative.”Since launching in 2009, Electus has aggregated a number of production outfits under its umbrella including a pair of firms already under IAC auspices — CollegeHumor and Notional — as well as bringing in DiGa Vision, led by former MTV topper Tony DiSanto, and DumbDumb, a joint shingle for Jason Bateman and Will Arnett.

While the phrase 5×5 is familiar to anyone who’s worked on a set — it’s radio terminology affirming signal strength, the equivalent of saying “loud and clear” — it’s also a reference to two other executives on the team. Guy Zajonc will lead business affairs and Mark Steilen is a writer/director who is hoping to put down roots for the company in scripted production.

“Fashion,” which is also produced by Magical Elves, will feature Elle Macpherson as host. She is also executive producer with Silverman, Ringbakk, Jane Lipsitz, Dan Cutforth, E.J. Johnston and James Deutch.