Michel Chevreul, a 19th-century French chemist, made discoveries about lipids that changed entire areas of manufacturing, and his theories about color influenced major artists. His ideas are still embraced and debated today. Textiles and dyes influenced Chevreul's color theory, and you can use his findings to help decorate your home.
Chevreul, already a noted and influential chemist, was hired by the Gobelin Tapestry factory to develop an antidote for their dulled dye colors and threads. His experiments and observations led him to theorize that tightly woven adjacent colored threads created a retinal impression of fading, moving the perception of the colors toward gray. In reality, the colors weren't dull or faded at all -- once the threads were separated. But the eye, according to Chevreul, wants to exaggerate the difference between two colors juxtaposed and viewed together in a process called simultaneous contrast. So, if you place a light gray and a dark gray next to each other, your eye will perceive the light gray as even lighter and the dark gray as even darker, to define the contrast. Separate the samples, and their true intensities are immediately apparent.
In this theory, all color works on the same principle. Chevreul stated that two colors in close proximity prompt the eye to "add" a residue of the color complement to each one. Think about what happens when you stare at a single color for a time and then look at a plain white surface. You'll see the successive contrast or negative afterimage -- the ghostly color complement of the original color -- in the same shape against the white. Red and green are complements, as are yellow and violet and blue and orange. Juxtaposed, complements intensify each other. But, if you place a red square next to a yellow square, your eye will begin to see a residue of the violet complement of yellow, dulling the red and a residue of the green complement of red, making the yellow murky. Remove those "ghost" colors by separating the red and yellow, and they seem more intense and brighter, more true in color. All that's really changed, however, is your perception.
The effect skews your perception for sequential colors as well. Look at a bright length of fabric -- say vivid red-orange silk. Now turn your gaze to a length of yellow silk. The negative afterimage of the first color is a bluish-teal, and it dulls the yellow in your mind. You "see" a less-saturated yellow because the overlay of the afterimage -- red and orange's complements of blue and green -- affect your perception. Chevreul called this "mixed contrast." If you are shopping for paint colors or new drapes, be aware that flipping through consecutive colors may not be giving you a true picture of what you are seeing. Look at decor colors against a plain white background, one at a time, to perceive their true saturation.
Saturation and Tone
Light Scales and Intensity
Color saturation is the maximum intensity of a color -- the bluest blue, the reddest red. Chevreul's scale of tones, gradations from pure white to mixes of a single color with a scale of white-to-black tones, depicts a color from pastel to darker and finally black. The color itself doesn't change saturation, but the amount of white or darker tone added to it lightens or obscures the pure color. A lighter color shows its strongest saturation closer to the white end of the graduated scale, and a darker color's maximum saturation shows closer to the black end of the scale. True yellow is found at a point closer to the white end; true purple is closer to the black end.
Playing With Colors
The paint chips in the hardware or paint store show a particular hue mixed with more or less white or black to cover a scale from pastel to a deeper tone. Choosing several colors from a single card results in a soothing color scheme -- same saturation, no contrasts. Juxtaposing a deep color against a dark neutral -- a cobalt wall behind a black leather couch -- highlights the color's intensity. Put banana-yellow cushions on a white-framed chair -- and the yellow pops. The same cushions on a slightly darker neutral -- a natural rattan chair -- don't seem as bright.
Van Gogh's Bedroom
When Vincent Van Gogh moved to Arles, the quality of light and his knowledge of color theory -- he read about Chevreul's complementary color theory and adopted it for his paintings -- inspired him to create vivid work in which true colors took a back seat to the effect of juxtaposed colors. Van Gogh was going for the emotion in his images when he wrote to his brother Theo about his selection of colors for his famous painting The Bedroom at Arles. The original work -- the colors have degraded over time -- had pale violet walls, butter-yellow bed frame and chairs, a red tile floor, brilliant lemon-green bedding and a scarlet blanket, a green window, an orange table with a blue wash basin, and a lilac door. He framed the painting in white, noting that his colors needed the white to bring out their intensity. Chevreul believed that white against pure color let the eye recharge and allowed the full saturation of contrasting colors to be seen. "[L]ooking at the picture ought to rest the brain, or rather the imagination," Van Gogh wrote to Theo, as he used every complement on the color wheel in his room.