Complementary colors are two colors that are on opposite sides of the color wheel. As an artist, knowing which colors are complementary to one another can help you make good color decisions. For instance, complementaries can make each other appear brighter, they can be mixed to create effective neutral hues, or they can be blended together for shadows.
Let's explore how you can use complementary colors to your advantage.
At the heart of color theory, complementary colors are the opposite hues on the color wheel. In their most basic form, they are one primary color and the secondary color that is created by mixing the other two primaries. For instance, the complementary color to yellow is purple, which is a mix of blue and red.
With that knowledge, it's rather easy to remember the first set of complementary colors:
If you add the tertiary colors—those made up of one primary and one secondary color—and work your way around the color wheel, you'll find that these colors are also complementary:
The color wheel can be divided up infinite numbers of times to include all gradients in between these basic hues. What is most important to understand is that no matter the shade or tone of the color, the opposite color is always its complementary.
One other thing you will notice is that a pair of complementary colors is made up of one cool color and one warm color. Orange, reds, and yellows are the warm colors, while blues, greens, and purples are the cool colors. This helps create what is known as simultaneous contrast, the highest contrasts available on the color wheel.
Simultaneous contrast occurs due to a natural illusion when you place two complementary colors next to one another. Both colors will appear brighter and grab a viewer's attention.
Artists use this to their advantage all the time. For example, sunsets with gradients from deep blues to bright oranges are more eye-catching because they rely on simultaneous contrast. Similarly, if your tube of red paint isn't bright enough, paint something green next to it.
When you're mixing paint, look to the hue's complementary first, because it can make wonderful things happen. For example, choosing to blend the complementary color into the main color of a subject is one of the best ways to paint dynamic shadows.
You can also use the complementary color to make a hue less vibrant. The more you add, the more neutral it becomes. For instance, adding a green paint to a red one will create a burnt sienna; add a little more and it becomes a darker sienna. If you mix the two paints in equal parts, you will get a warm-toned dark brown. These neutrals can be manipulated further by mixing in white, grey, or black.
Play around with these concepts and do some test mixing and sample swatches to see how your complementary paints affect one another. In general, if you're ever stuck on mixing or blending a particular paint, always consider its complement. Quite often, the answer to your problem is right there on the color wheel.