When you look at the rainbow, you can definitely see the primary colors. But unbeknownst to most people, the spectrum extends even further to some colors you can’t see. An example of which are the ultraviolet and infrared radiation that occurs outside the spectrum. So, barring color blindness, which is actually a genetic condition, there are still further examples of colors you can’t see. Scientists have often looked for ways to see both infrared and ultraviolet radiation. A neat trick taught by Robert Krampf to see infrared uses a remote control and a camera.
Infrared is commonly used by remote controls to communicate with televisions by using flashes of invisible light for each command. While it can’t be seen by the naked eye, the light can be caught on camera. However, it should be noted that ultraviolet and infrared are only two examples of colors you can’t see.
Robert Krampf Explains How To See A Color You Can’t See
There are more examples that we’re missing out on, and one such example are the so-called “forbidden colors.” It’s when our limitations to how we perceive colors kick in because of clashing stimuli in our brain. For example, red and green and yellow and blue. We perceive each color differently, which is why we can’t possibly imagine a color comprised of a mixture of red and green or yellow and blue.
In 1983, a paper by Hewitt Crane and Thomas Piantanida posits that under the right circumstances, the human eye can perceive the so-called “forbidden colors.” According to an article on livescience.com about the experiment, “The researchers had created images in which red and green stripes (and, in separate images, blue and yellow stripes) ran adjacent to each other. They showed the images to dozens of volunteers, using an eye tracker to hold the images fixed relative to the viewers’ eyes. This ensured that light from each color stripe always entered the same retinal cells; for example, some cells always received yellow light, while other cells simultaneously received only blue light.”
With the help of the eye tracker, the volunteers were able to view the “forbidden colors”. The researchers noted that the subjects saw colors that were “simultaneously red and green” or blue and yellow. An experiment in 2006 by Po-Jang Hsieh aimed to debunk the initial findings, with Hsieh claiming that the color that his test subjects saw was “mud” and that they were able to find the color through color mixing.
Vince Billock, a supporter of the 1983 research, argues that Hsieh’s experiment failed to take into account the use of the eye tracker which led to different results between the two experiments.
[Image via YouTube]