Color Theory: Human Color Perception

Color TheoryRelativityRelativity of Color: Humans are not machines

Color Scheme - 2025 - Three Philosophers

Human color perception is surprisingly subjective. Looking at the diagram above, almost no one would perceive the two small squares in the center as being the same color. Due to the relativity of color, appearances can change dramatically—a phenomenon rooted in the nature of human perception.

Color Perception and Surroundings

To gain a deeper understanding of this wavering caused by relativity, let’s examine a few more visual examples.

Two small purple squares of the exact same hue are placed side by side.

However, once different background colors are introduced, our visual system immediately loses its ability to perceive them accurately. (Despite the illusion, the two small squares remain the identical shade of purple.)

Once liberated from the constraints of relativity, our perception can recognize colors with far greater accuracy.

Relativity in Hue, Saturation, and Brightness

It is important to note that our visual perception diminishes when the surrounding colors are analogous to the subject but vary in value (brightness).

Conversely, even if the hue of the background changes significantly, the extent of the optical illusion remains relatively small.

Note: Using high-tone backgrounds (high value and saturation) can cause halation depending on the hue, making the color boundaries appear blurred.

Variations of Color Relativity

The lines and the small boxes on the left and right are all the same color.

All the small squares are identical in color. This is all the magic of relativity.

Beyond The Wall of Perception: Designing for Humanity

Unlike machines, human vision is inherently dependent on the surrounding environment; we cannot help but perceive colors through their relationships with others. In terms of recognizing objective color values, our sensory perception is far inferior to the precision of a machine.

What is truly fascinating is that this relativity is not limited to physical color perception. In situations where humans are forced to make a decision, their psychological judgment also wavers as the number of choices increases from two to three. (Reference: Psychology of Plan Selection in Subscribers)

Humans and machines are fundamentally different. It is vital that we keep these human characteristics in mind, striving for designs that incorporate universal accessibility, high visibility, and overall comfort.

After all, we design for eyes that dream,
not just eyes that scan.