July 15, 2021 | 1:12pm

While working with Bravo’s most famous faces on “Watch What Happens Live,” Caroline Blanchard is prepared for anything.

But in the end, it all comes down to, well, watching what happens.

“Sometimes people may show up late and then I have less time to do a whole hair and makeup [look], or their hair is wet, and they’ve only got half an hour,” the show’s lead makeup artist told Page Six Style.

“I’ve managed to finish everyone,” Blanchard added. “There’s no one that’s ever stepped out undone. It all just comes together.”

Hosted by Andy Cohen, the show is known for its anything-can-happen atmosphere — and according to Blanchard, backstage is no exception.

For instance, when the “Below Deck” cast stopped by for a recent visit, the makeup artist briefly stepped out to primp Cohen — only to return five minutes later to a “whole new room.”

“One of the cast members was getting a haircut all of a sudden … [Josiah Carter], I believe,” Blanchard recalled. “I’d hired the hairstylist, but we hadn’t talked about haircuts!”

It’s these sorts of spontaneous behind-the-scenes moments that Blanchard dearly missed during the pandemic, when guests had to appear remotely.

Sonja Morgan on
For a recent “WWHL” appearance, Sonja Morgan paired her all-pink ensemble with makeup by Blanchard.
Charles Sykes/Bravo

Rather than executing her usual in-studio glam, she was zooming (and Zooming) back and forth to help Bravolebrities look their best, texting last-minute beauty tips to guests like “Summer House” star Lindsay Hubbard.

“I had to get back to the studio to work with Andy, but I could see on the monitor that [the look wasn’t right],” Blanchard said. “So I was texting her, like, ‘Push your hair back, push your hair back,’ and finally by the third time she’s like, ‘Oh my god, I’m just seeing this!’”

Although things are feeling “brand new” now that everyone’s back in the clubhouse, there’s one thing that likely won’t be changing: Cohen’s go-to glam.

While the host’s longtime makeup artist joked that she lets him know when it’s “time for a haircut,” she keeps his beauty routine largely the same, save for switching foundations seasonally.

Andy Cohen in a blue suit
Blanchard has been working with Andy Cohen for over 10 years on “WWHL.”
Charles Sykes/Bravo

Blanchard’s close relationships with Cohen and Bravo have made her a mainstay in many “Housewives’” personal style squads, too. And while the franchise’s famed reunions and confessionals aren’t unfolding live like “WWHL,” there are still plenty of factors at play when it comes to primping.

Ahead of confessionals, Blanchard told us she sits down with the cast members to discuss not just their desired beauty looks, but also “how the mood is that day.”

“If someone isn’t feeling great, I suggest, ‘How about we just jazz it up and make you look absolutely fabulous? Let’s just knock it out of the park,’” she said. “Usually that kind of helps lift their mood.”

Luann de Lesseps on
Blanchard kept things “classic & chic” for Luann de Lesseps’ first “RHONY” Season 13 confessional.
Instagram

Makeup can also play a role in how “Housewives” are perceived by fans from episode to episode.

“If someone’s feeling feisty and they want to look a certain way, then we’ll execute that,” she explained. “If someone’s feeling that they want to be super nice, then we’ll make it a bit more demure. It all depends on the mood.”

And although the “Housewives” have been accused of many a Photoshop fail, Blanchard is fine with clients Facetuning her work — to an extent.

“I don’t think it’s a major crime to use a little bit of filter on an image,” she told us. “A little dusting never hurts. It’s just when [people] start to morph into other people, or a nose starts to fade out in the filter.”

Added Blanchard, “I don’t know that the public will always understand that there’s a filter, so they might wonder if work had been done. [But]I think people can do what they want with their own faces.”

Caroline Blanchard
Caroline Blanchard poses for a selfie of her own. The makeup artist recommends avoiding straightforward shots in order to best work your angles.
Instagram

After all, at the end of the day — or night, as the case may be — Blanchard’s makeup chair is there to give Bravo stars a break from the drama.

“We really don’t discuss their [on-screen] situations,” the makeup artist said. “I’m just really concerned about making them feel comfortable, making them look good and then getting them ready for the show.”