Impossible color

Color perception

Cones SMJ2 E

chimerical-color-demo

Impossible colors, NCS and RGB yellow and blue

Impossible colors, NCS and RGB red and green

Impossible colors are a concept within the field of color vision that refers to colors perceived in specific conditions that do not appear in the normal visual spectrum of colors. These colors, also known as forbidden or non-physical colors, are not present in the ordinary visible spectrum and cannot be produced by the simple combination of light wavelengths visible to the human eye. The study of impossible colors touches on various disciplines, including psychology, neuroscience, and optical illusions, offering insights into how the human brain processes and perceives color.

Overview

Impossible colors are not found in the typical color spaces used in color science, such as the RGB color model or the CMYK color model. These models define colors based on the combination of primary colors (red, green, blue for RGB, and cyan, magenta, yellow, and key/black for CMYK) that, when mixed, can produce a wide range of visible colors. However, impossible colors fall outside these combinations, suggesting that our understanding of color perception is not solely based on the physical properties of light but also on how our brains interpret these signals.

Types of Impossible Colors

There are several types of impossible colors, including:

- Chimerical colors: These are hypothetical colors that are perceived when one part of the visual field adapts to a certain color, and another part is then exposed to a different color. An example is "hyper-blue," a color perceived as more saturated than the purest form of blue visible in the normal color spectrum.

- Self-luminous colors: These colors appear to be glowing from within, unlike any color seen in the natural world, where colors are perceived based on reflected light.

- Hyperbolic colors: These colors are described as more intense versions of normal colors, such as a green that is greener than any green achievable through the visible spectrum.

Perception and Experimentation

The perception of impossible colors can be induced through specific visual exercises or experiments. One common method involves staring at a colored image for an extended period (a process known as color adaptation) and then quickly looking at a white surface, where a "negative afterimage" in an impossible color may appear. These experiments suggest that impossible colors are not inherent in the light spectrum but are constructed by the brain's interpretation of visual information.

Implications

The study of impossible colors has significant implications for our understanding of color perception and the brain's processing of visual information. It challenges the notion that colors are purely a function of the physical properties of light, suggesting instead that they are a complex interplay of physical, neurological, and psychological factors. Research into impossible colors could contribute to advancements in color theory, visual arts, and the development of new technologies for color representation and reproduction.

See Also

• Color vision
• Optical illusions
• Color theory
• RGB color model
• CMYK color model