Here's what Ridley Scott's masterpiece can teach you about using color in your own work.

Adapted from Phillip K. Dick's novel Do Androids Dream of Electric Sheep?, Ridley Scott's 1982 film Blade Runner is a classic of science fiction, as well as a deeply subversive movie. (Its dystopian world defied all the "rules" at a time when Star Wars had codified the genre.) Over the years, its troubled production history and many cuts have led to near-Shining levels of devotion to and debate over the film's meaning.

Rob Ager of Collative Learning recently looked at the use of the color red in the eyes of the characters (and the mise-en-scène of the film itself). It shows how, by looking at a small piece of the film, larger thematic trends are revealed; the visual ambiguity inherent in the movie is valuable for any filmmaker to contemplate.

It's always difficult to translate a novel to the big screen. As an almost entirely visual—as well as ruthlessly temporal—medium, film demands that the subtleties of fiction find a visual correlation that, in all likelihood, will be lacking from the written work. The two operate on different plains of symbolic logic (verbal and visual). From the beginning of the film, Scott uses the image of the eye—and especially the "red" eye—to telegraph meaning to the audience. But what is that meaning?

"The eye is really the most important organ in the human body. It's like a two-way mirror; the eye doesn't only see a lot, the eye gives away a lot."

In the film, Harrison Ford's character, Rick Deckard, is a Blade Runner, or a member of a "Special Police Squad" tasked with the elimination of replicants, a form of advanced A.I. and perceived existential threat to humanity following a bloody mutiny. Replicants are difficult to discern from humans and must be given psychological tests to determine their humanity, or lack thereof. Deckard's love interest, Rachel (Sean Young), is both a replicant and an "experiment"; she has been given implanted memories to protect her from realizing that she is a replicant, thus will only live for a few years. The illusion of humanity subdues her.

While red eyes appear throughout the film, and some of them appear on replicants, Ager quotes a forum member who said, "If replicants do have a natural red-eye effect, then why do Blade Runners bother with all that psychological testing? Why not just shine a light into their eyes?"

The common and usually undesired photographic effect of red eye occurs "when a camera flash goes off [and] the pupils of your subject's eyes don't have time to constrict to reduce the amount of light entering their eyes .... a large burst of light reaches their retinas, reflects back, and is captured on film." The redness that is captured is from blood vessels at the back of your eyes; paradoxically, this most human of features commonly represents artificial intelligence in science fiction (think The Terminator, or Hal 9000).

In the above scene, a replicant is given the so-called Voight-Kampff test, a series of questions that are innocuous to humans, but that reveal the true nature of replicants, who are unable to answer them properly. The test is administered by a machine with a rather prominent red dot at the center of a circle; and yet, the eyeball shown on the monitor screen in the clip above at 1:44 seconds, which belongs to Leon, who is a replicant, is green (the same eyeball is shown in Rachel's test at :39 seconds in the clip before that, though the characters have brown and blue eyes, respectively). According to Ager, the eyeballs on the monitors are actually stock footage. The symbolism is not uniform and appears to follow little rhyme or reason.

But notice, in the explanatory titles at the beginning of the film, that the only word that appears in a color is the word "Replicant"— in red. Ditto for the eye in the sign outside Eye World, a store where the eyes of several replicants have been manufactured.

Ager believes that the reason for the seemingly capricious use of red eyes in the film and its characters—as well as the inconsistency with which it's deployed—is because "it's there for the audience, not the characters. In other words, it's metaphoric."

In another shot from the opening credits, we see the city and fire reflected in an eyeball, but this is not tied to any specific character. It could be said to represent the eye of the audience, who is going to receive knowledge that will be denied the characters. (Though the shots are edited to give the impression that they are coming from Deckard's POV, this spatial-temporal relationship is never clarified, and, in fact, he's shown in a room where he couldn't be looking at the vista reflected in the eye).

Credit: Warner Bros.

Scott, who believes that Deckard is himself a replicant, has said of the glowing eyes, "that kickback you saw from the replicants' retinas was a bit of a design flaw. I was also trying to say that the eye is really the most important organ in the human body. It's like a two-way mirror; the eye doesn't only see a lot, the eye gives away a lot. A glowing human retina seemed one way of stating that."

It's also interesting to note that Dick believed Deckard to be human; so did Hampton Fancher, the film's screenwriter. Of course, the symbolism goes far beyond just the issue of eyes (there's also the issue of the 1940's wardrobe and other elements of film noir aspects, as well as the environmental catastrophe and destruction of nature); Blade Runner is one of the most symbolically and thematically rich modern Hollywood films. Scott allows for a degree of ambiguity in the story, Ford's character, and the world which he and the replicants inhabit, and this is, arguably, why the film is such an important work of art today, 34 years since its release. It's an object lesson for filmmakers, too, and a standard to test the tensile strength of your story: when you can pile uncertainty upon uncertainty and maintain a coherent work that can withstand multiple interpretations, then you've done your job. By that measure, as well as many others, Blade Runner is a triumph.