In EvilThe evil future witch Elphaba (Cynthia Erivo) is ostracized by her fellow Ozians because of her green skin and magical powers. But on the set of a big-budget Hollywood studio production that relies heavily on visual effects rather than magic, it has its own colorful enemy: green screen technology.

Vibrant green backgrounds – often referred to as “chroma green” by digital artists – are used in modern VFX processes, in part because this hue is so far removed from the color range of human skin. This makes it much easier for visual effects artists to digitally select and replace anything in an image that has chroma green by keying out the actors and inserting them into new backgrounds. But if Elphaba stood in front of a green screen backdrop, it would likely wipe her out like her classmates want, theoretically leaving an equally magical floating hat, eyes, dress, and cape as a replacement for the Wicked Witch of the West.

As Pablo Helman, visual effects supervisor at Industrial Light & Magic, explained in an interview with Polygon EvilAfter the release of Elphaba, Elphaba’s coloring made it necessary to resort to an earlier form of this type of digital replacement technology.

“It immediately became a blue screen show,” says Helman. “As you prepare, you have to get all these screens. And so we knew we had to use a blue screen.”

Helman, whose visual effects achievements range from fantastic films like… Star Wars: Episode II – Attack of the Clones to less visible works on Martin Scorsese The Irishman – prefers to use these screens as little as possible: “The reason I don’t like (this method) is that it changes the lighting by spreading it across the entire set, to one color or another.” In his Eyes, that would have taken the life of one of them Evilis one of the year’s most lavish musical numbers, with Prince Fiyero (Jonathan Bailey) leading Galinda/Glinda (Ariana Grande) and others in a cheerful song about “Life is more painless/for the brainless.”

“For example, scenes like Dancing Through Life in the library could have been a blue screen set because that’s where all the backgrounds were,” says Helman. “But I worked with Alice Brooks, the cinematographer, to say, ‘If we think we’re exposing the inside and the outside is blooming, then let’s just light it white and go for it.’ We have to extract the actors and place the backgrounds differently because then the white light will help us understand the true meaning of what it means to be in a set like this.’”

The contrast between the bright white light that Brooks and Helman wanted for this scene and the blue light that digital backgrounds would have spread throughout the sequence is part of the frustration Helman often experiences on film sets, where different requirements for a shot Conflict can occur.

“If you actually look at the beginnings of green or blue screen photography, it’s because in visual effects we like to separate everything and we love to have control over everything,” he says. “But the director also wants to be in control, and the production designer wants to be in control.”

Despite all the preparations, Helman, director Jon M. Chu (Crazy rich Asians, In the heights) and the rest of the filmmaking team involved in the project, it wasn’t until they were on set that they realized that avoiding an Elphaba-green screen conflict meant getting in its way another Problem.

“Before we started filming at Shiz (the university in Oz), we didn’t realize that everyone was wearing blue,” laughed Helman.