Simultaneous Contrast

How red is red? That depends in part on its context. We see colors in relationship to other colors in our field of vision. The appearance of any one color is modified by the presence of other colors. (This is a perceptual effect, not a physical effect; while we experience it, we cannot measure it physically.)

Once you identify the elements in play, you can predict the effect. Simultaneous contrast can occur between any one or multiple components of the three elements of color – luminosity, hue, or saturation.

Place dark colors next to light colors and the dark colors will appear darker and the light colors will appear lighter.
Place cool colors next to warm colors and the cool colors will appear cooler while the warm colors will appear warmer. (Additionally, complementary hues increase each other’s saturation.)

Place saturated colors next to less saturated colors and the desaturated colors will appear less saturated while the saturated colors will appear more saturated. (Additionally, the desaturated color will appear to contain a cast of the saturated hue’s complement.)

Want to make a color appear lighter? Make it lighter or make surrounding colors darker or both. Want to make a color appear warmer? Make it warmer or make surrounding colors cooler or both. Want to make a color appear more saturated? Make it more saturated or make surrounding colors less saturated or both.

Contrast (or lack thereof) is the engine that drives color dynamics. To intensify a visual effect, increase the contrast in the appropriate components of color. This effect is intensified between adjacent colors. It is further intensified if one color surrounds another, partially or entirely. (If a color dynamic is particularly intense it may create the visual appearance of a line separating the two fields of color. Op artists often use these effects to create highly dynamic visual effects that appear to pulsate or move.)

Color management doesn’t yet accommodate these kinds of perceptual effects. Standard color correction strategies don’t tend to address them. But you can incorporate them into your color adjustment methods for greater precision and/or expression. All you need to do is take note of them and make appropriate compensations to achieve the result you desire.

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Optical Illusion – Silencing – Motion Silences Change

Silencing is an optical illusion that shows motion (of objects or the eyes) makes it harder to notice changes in appearance. What once appeared dynamic appear static. Silencing affects changes in color, brightness, size, and shape.
Play the movie while looking at the small white speck in the center of the ring. At first, the ring is motionless and it’s easy to tell that the dots are changing color. When the ring begins to rotate, the dots suddenly appear to stop changing. But in reality they are changing the entire time.

Motion silences awareness of color changes from Jordan Suchow on Vimeo.

Motion silences awareness of brightness changes from Jordan Suchow on Vimeo.

Motion silences awareness of size changes from Jordan Suchow on Vimeo.

Motion silences awareness of shape changes from Jordan Suchow on Vimeo.

These demos were created by Jordan Suchow (suchow@fas.harvard.edu) and George Alvarez, and first appeared in a paper in Current Biology.
Find resources on color theory and color psychology here.
Learn more in my digital printing and digital photography workshops here.