When it comes to colour (theory), there are three things that I have always found intriguing in both design and painting: colour influence, the after-image effect and partitive colour.
Colour influence occurs when one colour spectrally changes or alters another. Most commonly, highly saturated colours can do this. In painting, strongly pigmented hues like Ultramarine for example, lying next door to an orange like Cadmium, can change the intensity to either dull it down to a light brown, or shift it more towards the magenta, creating an optical salmon. This is an effect that Mark Rothko used in his famous paintings such as this one…
Note: Even though Rothko was classified as an abstract expressionist, he hated the term and classified himself as an “abstract painter”. I personally place him squarely in the realm of colour field painting.
In the sample above, you can clearly see how Rothko took great care in choosing each hue. Even the background is selected with great care and to great affect. The purple cast plays a primary role here and makes the Burnt Sienna tones “pop” due to the yellow in the sienna reacting with the background. The dark Prussian blue which is mixed with just enough green to give the colour a greenish cast, making it pop as well, because it’s also reacting to it’s dark plum background. The top bar, painted in muted reds, browns and violets has bits of red, making it link to the red in the background analogously and stabilizing the two lower bars because optically, it appears just slightly larger than the other two bars below it. The overall effect is that of enhancing and punching up color hues a notch or five.
The after-image effect is related to colour influence but on a more physical side. The after-image effect is something that happens to everyone on a bright sunny day. When you look at the sun and then go indoors, you are momentarily blinded. The rods and cones in your eyes are fully saturated with so much colour, you can’t focus for the first few seconds. Coming in from the brightly lit outdoors, the inside of your house will appear in shades of blurry grays and blacks. A few seconds later your eyes clear and you can see again. What you were seeing is actually the opposite colour to the brilliant colours from outside.
You can make it happen too. Above are two images. If you block the other images and stare at the first blue image with the green chair for 30 seconds and then do the same to the red image, you’ll see the effect. The result is actually quite predictable.
You should see a pink glow around the blue chair as you stare at the second image. That is the after-image effect. Your eyes are trying to adjust to seeing more saturated colour than they can handle by creating the effect. The pink is exactly halfway between these two colours so you see a pink or magenta glow around the green chair.
This colour wheel matches the RGB gamut used in the images above it.
Partitive colour is something we’ve all seen before. We see it in printing when printers use coarse screens and it’s the basis behind the short-lived pointillism movement in painting from the 1880’s. Also known as retinal mixing, it’s what happens when you look at small points of pure colour blended with other points of pure colour. Your eyes create the intended colour by optically mixing. It’s a remarkable effect when you think about it. Interestingly, you can’t stand close to these images to see the effect, but far away. (Think comic books of the 60s or Roy Lichtenstein).
Here is what you’re actually seeing. The first image is a close-up, the second is from viewing at a distance and the third image is what your eyes “think” they are seeing.
In printing, this is an example of a typical application of partitive colour. To see this image clearly, take three steps back.
Because life is colourful.