Our experience of visual perception is not absolute; it is shaped by a sensory perception of relationships. This applies similarly to our perception of color and of dark/light relationships.
The slide-bar graphic above offers an opportunity to experience this. The inside square is a fixed value, but if you work the slide bar to change the dark/light value of the square that surrounds this inner square, the inner square will appear to change. This is a demonstration that our perceptions are based on an assessment of relationships; there are no absolutes.
In his book Interaction of Color, Josef Albers uses a tactile water temperature analogy to describe the relative nature of color perception. Set up three bowls of water, one hot, one cold, and one lukewarm. If you put one hand in the hot water, the other in cold water, and then, after a minute or so, put both into the lukewarm water, the temperature of the lukewarm water will not feel the same to the two hands. By working the slide bar below the graphic above, you can demonstrate for yourself that the same principle applies to our visual perception of color.
Seek to focus your gaze on the black cross in the square above. You may notice, with some concentrated effort to keep your gaze fixed, the colors begin to fade. If you really concentrate, you may be able to get the colors to fade almost entirely (and get the square surrounding the blurry colors to go entirely white). The instant you shift your gaze, or perhaps even just blink, the colors will re-appear.
This graphic, known as The Troxler Effect (first noticed by Swiss doctor Ignaz Vital Troxler in 1804), demonstrates graphically that it takes two phenomena for us to experience color:
1. Our eyes need to be moving. Mostly we are unaware of the rapid eye movement called micro-saccades that helps generate our sensation of color sensation. The success of this exercise is related to our ability to quiet this rapid eye movement.
2. We need to be perceiving light of differing wavelengths. The sensation of color is all about the perception of light of differing wavelengths. The differing wavelengths are an expression of light carrying different energy levels. Our Energy Theory of Color is an outlook that emphasizes our visual perception as an assessment and experience of these energy relationships.
Visual perception is built from a discernment of relationships. This is true of both color relationships and relationships of darks and lights. In this exercise the gray circle appears to grow lighter or darker in relation to the surrounding values, but actually remains constant in its value.
Color constancy describes how our brains process relational information, especially clues related to light and light sources, in our assessment of color relationships. Despite changing lighting conditions, we perceive objects as maintaining relatively constant colors. A red apple appears red whether it's in bright sunlight or dim candlelight, even though the actual wavelengths of light reflected from it are quite different in each situation.
This graphic demonstrates color constancy in action. The three circles maintain their core colors (red, green, and yellow) across different lighting conditions. By toggling between daylight, sunset, and candlelight, you can observe how the background and overall scene lighting changes, while the circles themselves maintain their color identity. This is a demonstration of how our visual system uses contextual information about lighting to maintain stable color perception—another example of our perception being based on an assessment of relationships rather than absolute values.
Move your mouse over the pattern to keep it visible
This graphic works similarly to the Troxler Effect above (Concept 3), demonstrating how our visual perception prioritizes the perception of change. Note, however, that this graphic is enhanced. The fading is not just in your perception, the little dots are set to fade away, offering an enhanced experience of how our perception of not only colors but of all visual relationships is reliant on eye movement.
The term sensory fading describes how our perception focuses on moving or changing images, and that static images tend to fade.
In 2015 a photo image went viral on the internet. Is the dress in the photo blue and black, or white and gold?
The photo is a demonstration of the color constancy principle outlined in Concept 5 above. Our idea of the colors of the dress is actually formed by assumptions about the lighting in the photo, i.e. whether the dress is in direct sunlight or in shadow and backlit.
Simultaneous contrast describes how adjacent colors influence each other. In this demonstration, we compare two identical reds and two identical cyans.
Notice how the blocks that are "trapped" behind the vertical bars appear different in hue and intensity compared to the blocks that sit on top of the bars. By changing the spatial relationship (behind vs. in front), our perception of the color shifts, even though the actual pixel color values remain identical.
This demonstration uses the Arabic word for beauty, "Al-Jamal”, in yellow/gold text. It illustrates simultaneous contrast alongside the visual concept of assimilation. A dictionary will often describe assimilation with auditory references, sounds that bleed or blend into adjacent sounds. The gold text is identical on both sides, yet our perception of it changes based on its relationship to its surrounding pattern.
Left Side (Contrast): When the word sits in front of the veil, the gold contrasts sharply against the dark background, appearing brighter and more vibrant. The eye perceives the gold as more luminous because it stands in opposition to the dark lines.
Right Side (Assimilation): When the word is placed behind the veil, the dark lines of the pattern visually mix with the gold text, making it appear darker and more muted. In this example of assimilation the adjacent dark lines "pollute" or shift our perception of the gold beneath.
By toggling the veil and comparing the two words, you can observe how the same color changes base on its relationship to adjacent colors. It demonstrates how color perception is shaped by the energy relationships between colors (a core principle of the Energy Theory of Color).
This mosaic pattern from The Alhambra in Granada, Spain, demonstrates how shifting the overall energy level (or "greypoint") of an image dramatically alters the relationships between the colors.
Low Energy (Left): As you shift the energy towards the darker end, the deep blues and greens become dominant, while the gold lattice recedes into the shadows, creating a moody, mysterious atmosphere where the "ground" becomes more substantial than the "figure".
High Energy (Right): Shifting towards the lighter end energizes the entire field. The gold lattice becomes radiant and piercing, pushing forward as the primary figure, while the blues and greens lose their depth and become supporting pastel tones.
We often speak of color as if it were an inherent property of an object—"the apple is red." However, color is a construction of the mind, a subjective experience generated by how our specific biological hardware processes light energy.
Dog Vision: Dogs are dichromats (blue + yellow-green sensitive), so reds lose contrast and many scenes compress into yellow-blue-gray relationships. In ETOC terms, the same physical light carries a different felt energy map for a different visual system.
Cat Vision: Cats also have dichromatic color vision and lower daylight acuity, so warm hues flatten and fine detail softens. The simulation highlights a core ETOC point: perception is not just color names, but energy relationships shaped by the observer.
Bee Vision: Bees read UV, blue, and green (not red), revealing nectar guides we cannot naturally see. This art-science translation uses false-color mapping to suggest how hidden energy structure appears when the visual apparatus changes.
Bird Vision: Many birds are tetrachromats, adding UV sensitivity to the spectrum and expanding color distinctions beyond typical human vision. The rendering is an approximation, but it supports the ETOC view that "what is seen" depends on the observer's sensory design.
Papilio Butterfly: Papilio xuthus has exceptionally fine spectral discrimination across multiple receptor classes, so tiny hue differences become highly legible. Here we compress that richer perception into visual cues that connect scientific findings with artistic experience.
Color Blindness (Protanopia): With missing long-wavelength (L-cone) response, reds shift toward yellow-brown and familiar contrasts reorganize. This reinforces ETOC's central claim: color experience is subjective, relational, and built by perception.
To learn more about how researchers capture animal vision—including UV—see Animals Can See Colors We Can't (Scientific American, 2024).
Every human visual system is unique. We all prioritize different relationships in light and color.
You see structure in light. You perceive the world as a built environment of energy.
This interactive assessment explores your personal subjectivity. By choosing what catches your eye, we can infer how your visual cortex prioritizes information—whether you seek structure, emotional magnitude, contrast, or hidden depth.