You’ve seen "The Wizard of Oz," right? When Toto pulls the curtain back on the Wizard, it mightily disappoints Dorothy and her entourage, prompting her to say, "You’re a bad, bad man!"

There’s no such discouragement in venturing behind the curtain for "Wicked," the contemporary musical take on the land of Oz and its witches now playing at Blaisdell Concert Hall.

Eyeing the action backstage, where you find the costumes, props, green room and dressing rooms, only reinforces the magic of this production. The windowless rooms have a bunkerlike feel, but look, against this wall: the long rakes and pitchforks to be brandished by Oz’s angry mob! Over there: the golden face of the terrible Oz!

Chorus members glide by, almost floating and already singing. A handsome man dressed in stage finery smiles and nods as he walks past.

In the "green room," costumes get a steamy touch-up. Standbys joke with principals. A winged monkey slips by, glimpsed down a dark hallway.

And in a dressing room a slight, clear-eyed woman tucks her hair up, pulls on black tights and slips into a green mesh top.

The witch we call wicked is about to take form.

THE PRODUCERS of "Wicked" gave the Star-Advertiser backstage access last week to see how Dee Roscioli transforms into Elphaba, the green-skinned outcast who becomes a defiant, feared heroine.

Roscioli gets her green tint via a rather magical process, but it’s not high-tech. It’s based on using the right materials and having a skilled crew member to help out.

The green pigment itself comes from M.A.C. Cosmetics, which makes theatrical face paint. Seen up close, the makeup is velvety and attractive.

"A lot of people misunderstand this makeup at first," makeup artist Christina Tracey said. "They think she’s supposed to be ugly, but it’s quite the opposite. The green is a very pretty, soft green, and her makeup is going to be beautiful by the time we finish it."

Tracey applies it with a brush, using airy, circular strokes.

"I’m buffing it and sort of using it as a watercolor," noted Tracey. "I’m making it look airbrushed, creating air under the brush to make it look flawless and seamless."

While Roscioli got ready, trilling vocal phrases (and a couple of sharp cries) rolled through the air. Patti Murin, the actress playing Glinda (aka Galinda), was warming up in the next room.

"Sometimes people think I’m wearing latex or gloves," Roscioli said. "I have long fingers; people ask if I have finger extensions. It’s very simple … just makeup!"

She sports green fingernail polish. And a sheer silk top, which comes down over her hands and arms like an open-toed stocking, eliminates the need to paint her arms or chest.

Relaxing? "It is, actually," Roscioli said. "(Tracey) has a very light touch, so it’s very pleasant. But usually my door is always open. It’s usually very high-energy, lots of people floating in and out. So there isn’t a lot of time to relax."

After the first green layer goes on, Tracey applies green concealing cream to delicate areas that can’t be reached with the brush, around the eyes, nose and lips.

A dusting of powder sets the makeup. "Once the powder is applied, it pretty much stays put," Roscioli said. "And I don’t seem to sweat a lot during the show, on my face, at least — which is nice, because then I have minimal touch-ups during the show."

Extra "catch powder" is left loose on her cheeks, to catch any overflow of dark powder from her eyeliner or brows so that it can be simply brushed away.

"The green flattens everything out," Roscioli explained, so black powder is used to create contouring shadows at her cheeks and chin.

Roscioli applies green lipstick, eyeliner and mascara herself.

She wears a cap over her hair. Hair supervisor Lisa Thomas threads tiny microphones, the size of small beads, over Roscioli’s head. A wig is laid over that.

"It’s the green team," Roscioli said.

Then Roscioli pulls on her boots and her severe scholar’s dress, with just minutes to go before the curtain rises.

The entire process takes 30 to 40 minutes, start to finish.

YOU MIGHT WONDER whether Roscioli starts to feel more like Elphaba as she turns more green.

The answer is no.

"I really don’t get into character until right before I go on," she said. "I take a few minutes right before I make my entrance. Because at this point I’ve done the role a very long time, and I think it’s so ingrained in me now. I don’t need to get into the character. It just happens."

Roscioli has played Elphaba more times than any other actor, including stints on Broadway in 2009, in Chicago and with the touring production.

She’s played the part more than 1,000 times. That means a lot of time spent turning green. At this point she’s focused and matter-of-fact about the work.

"My favorite part is the green in my ears," she said, with a hint of the same kind of sarcasm Elphaba would use. "Wouldn’t that be anyone’s favorite part?

"There have been times when I’ve ended the show — ended a contract with the show — and I would find green in my ears for at least a week afterward."

In the first half of the play, Elphaba is an adolescent, learning the sometimes cruel ways of the world.

"Her whole character goes through a huge transformation for the second act," Tracey said. "Everything from her acting to her wardrobe, makeup, hair.

"First act is a younger, more immature, innocent makeup, and then second act is a sexier, smokier black eye. She’s got a little more drama."

In the second half, Elphaba is a woman, and she faces life-or-death decisions.

"It’s a journey," Roscioli said slyly.

Roscioli said she recently got a tip that Neutrogena soap removed the green makeup easily — and found that it did. After using more painstaking methods to remove the paint for hundreds of performances, now "it just washes away," she said.

As she spoke, Murin stepped into Galinda’s heavy blue gown in the room next door to prepare for her airborne entrance. And down the hall, a monkey stood in the wings.