Gray Means Stop Illusion

In this Gray Means Stop Illusion, the traffic light on the left is a perfectly normal signal, but the one on the right is a trick. Although it appears red, the top light is actually gray.

The Gray Means Stop Illusion works due to how the brain red due to the phenomenon of color constancy.

If you are interested in learning more about color constancy works in the Gray Means Stop Illusion, scroll down to read more about it.

If you want to see some proof that I’m not lying about the “red” light in the right traffic light, click here to see for yourself.

What is the Color Constancy – Gray Means Stop Illusion?
How does Color Constancy – Gray Means Stop Illusion
Some Similar Illusions
Discovery of the Color Constancy – Gray Means Stop Illusion
References and Resources

What is the Color Constancy – Gray Means Stop Illusion

Color constancy is the phenomenon where the perceived color of an object remains relatively constant under different lighting conditions.

The color constancy illusion can cause us to misjudge or perceive colors differently based on their context or surroundings. Our brain often adjusts our perception of an object’s color to account for changes in lighting or context, allowing us to see colors relatively consistently across different environments.

How does the Color Constancy – Gray Means Stop Illusion

The Grey Means Stop Illusions works due to color constancy which works through a process known as chromatic adaptation. Chromatic adaptation is the ability of the human visual system to adjust its response to different lighting conditions, in order to maintain a relatively constant perception of the color of objects.

When we look at an object, the light reflecting off it enters our eyes and stimulates the cone cells in our retina that are responsible for detecting color. These cone cells are sensitive to different wavelengths of light, and they send signals to our brain that are interpreted as color.

However, the color of the light that illuminates the object can vary widely, and this can affect the color signals that are sent to our brain. In order to compensate for changes in the lighting conditions, our visual system adjusts the sensitivity of our cone cells to different wavelengths of light. This process is called chromatic adaptation.

When our visual system encounters a scene with different lighting conditions, it first identifies the overall color of the light in the scene. It then adjusts the sensitivity of the cone cells to match the spectral properties of the light, in order to maintain a consistent perception of color. This adjustment process occurs automatically and unconsciously, allowing us to see colors accurately despite changes in lighting conditions.

However, in some situations, such as when an object is surrounded by colors of a different hue or brightness, the color signals sent to our brain can be influenced by the context in which the object is viewed. This can lead to color constancy illusions, where our perception of an object’s color is affected by the surrounding colors or context.

Some Similar Illusions

Here are some other optical illusions similar to the Gray Means Stop Illusion that you might find interesting:

This Chromatic Adaptation Illusion allows you to see a black and white image in full color.
Chromostereopsis is an optical illusion that involves the perception of depth and three-dimensionality based on color information. It is caused by the differential refraction of light of different wavelengths, known as chromatic aberration, as it passes through a lens.
The Bezold Effect is a phenomenon in color theory where a change in one color can cause the perception of the surrounding colors to change as well.
Moiré patterns: These are patterns that appear when two overlapping patterns with slightly different frequencies or orientations are superimposed.
Color Afterimages: After staring at a bright color for a period of time, you might see an image of that color when you look away.
Stereograms: Stereograms use a combination of two images that are slightly offset from each other to create the illusion of depth.
Binocular rivalry is a phenomenon that occurs when slightly different images are presented to each eye simultaneously.
Troxler’s fading, is a phenomenon in which a stationary visual stimulus eventually disappears from perception, even though it is still present in the visual field.
The Scintillating Grid Illusion, in which a grid of black and white squares appears to pulsate or “breathe” when viewed from the periphery of the image.
Silencing is a visual phenomenon where objects that change in luminance, hue, size, or shape appear to stop changing when they move. They “freeze” in place.

Discovery of the Color Constancy – Grey Means Stop

The phenomenon of color constancy that underpins the Gray Means Stop Illusion has been observed and studied by many scientists throughout history, but it was first described in detail by Johann Wolfgang von Goethe, a German writer, poet, and philosopher in his 1810 book “Theory of Colours.” Goethe observed that the perceived color of an object was affected by the color of the surrounding area, and that the human visual system was able to adjust its perception of color to compensate for changes in lighting conditions.

Later, in the 19th and 20th centuries, researchers such as Hermann von Helmholtz, James Clerk Maxwell, and Edwin H. Land, among others, conducted experiments and developed theories to explain the mechanisms behind color constancy. Today, color constancy remains an active area of research in vision science, psychology, and neuroscience.