1⁄35Introduction to Shading with Complementary Colors
Before going any further it would be best to define some common terms for anyone unfamiliar with them.
|Hue||The specific character of a colour, e.g. an orange-red or a green-blue, its position on the colour wheel.|
|Value||How dark or light a colour is, from 0 to 10, black to white. Cadmium Red Medium is typically about value 5.|
|Chroma||How intense (bright or dull) a colour is, for example Cobalt Blue is high in chroma, Chromium Oxide Green is low in chroma.|
|Primary||A colour that cannot be mixed from other colours, e.g. red, yellow and blue.|
|Secondary||A colour mixed from two primaries, e.g. orange, green and violet.|
|Complement||The colour opposite to another on the colour wheel, e.g. red and green, yellow and violet, blue and orange.|
|Subdue||To dull down, to lower the chroma of a colour, usually by adding its complement.|
|Bias||The leaning of a colour towards another, e.g. a green-yellow or an orange-yellow.|
Theory & Practice
Please forgive the boring theory but as you will see a good understanding of the nature of a given colour and how it relates to others will allow you to foresee the inter-reaction between them with a fair degree of accuracy which will save you a great deal of time and, ultimately, paint. The colour wheel is a good theoretical model for colour mixing but has a basic flaw: true primaries don't really exist and by extension, neither do their complements. For example, if you could find a true red and a true yellow with no bias, as a typical colour wheel implies, when you mixed them together you would not get orange as you would expect, instead it would yield a dark grey, nearly black - a pure red and yellow would only reflect red and yellow light respectively and when mixed would cancel each other out. Now we all know you do in fact get an orange if you mix red and yellow. This is because in the real world colours only fall roughly into hue positions because all pigments also reflect other colours. If we take 'red' for example, invariably some orange and violet light; in the case of yellow, some orange and green light. The other colour they reflect the most of will be its bias, a leaning towards that colour, hence an orange-red or a green-yellow. So if we want to mix a bright, high chroma, orange we know we need a red and a yellow both with an orange bias and Cadmium Red Light and Cadmium Yellow Medium fit the bill. Conversely, and more useful for our purposes, if you want to mix a duller orange you might pick a red with a violet bias which with the same yellow will give a lower-chroma result. If you take this further by choosing a red and a yellow that both lean away from orange, a violet-red and a green-yellow, you will get a very subdued result which is what happens when you mix a crimson with a lemon yellow.