Our brains are incredible. They take in the lights and shadows that our eyes capture and they interpret this information to help us understand our surroundings. They sort through a tremendous amount of stimuli and quickly process everything we perceive.
This is great, but as an artist, there's just one downfall. To sort through so much information in a fraction of a second, our brains have developed techniques that simplify what we see.
For instance, we are already aware of what "an eye" is supposed to look like. So, when we see eyes during our day, our brains find it unnecessary to stop and look at every single pair of eyes in detail.
As artists, this makes the task of rendering a subject realistically difficult. It's easy to fall into the trap of assuming we know what something looks like without ever studying the details.
When it comes to shadows, our brains do the same thing.
We've seen countless shadows in our lifetime. We relate shadows to darkness, and darkness to black. Therefore, our brains are generally preprogrammed to assume that shadows "are gray." But if you stop for a moment and look around you, you'll see that there's a depth to shadows that we rarely pause to take in.
Shadows have warmth, coolness and depth variations that we fail to capture in our paintings if we choose to use only black or gray tones to paint them.
There isn't any natural presence of true black in our environments, so when we use it in our paintings it can look unusual or like something's not quite right. When you mix black or gray color into, say, red, the result is a dull mixture that doesn't look lifelike.
How can we darken our hues to mix watercolors that will create beautiful shadows?
The trick is avoiding using black and gray tones and instead use complementary colors.
Complementary colors are a pair of colors that are placed opposite each other on the color wheel.
Pairs of complementary colors are made up of one warm hue and one cool one. This means that when placed beside one another, they make each other stand out more. When mixed together, complementary colors can make the perfect hue for shadows with more depth.
Why create shadows this way? Complementary colors darken each other while lowering their vibrancy and neutralizing each other without creating a dull color as a result.
How to use complementary colors to paint shadows in watercolor
It's always exciting when I get to bring out my handy dandy color wheel! There you can easily see which colors are complementary and which hues to mix to create some nice shadow colors.
Above you can see a few examples: I've mixed three pairs of complementary colors to see how they come together into a neutral tone.
As you can tell, the mixed colors are all quite different and have different undertones. You can manipulate these undertones to work well with your composition. The results will vary depending on the ratio of the colors in your mix and how watered down your watercolors are. The great thing about this is that it's fun to experiment until you achieve the hue you like.
For example, for the first swatches, you could add more green to the mixture to create a cooler undertone. Or, you could add more red to push it over to the warm side.
In these quick cube examples, you can see better how each cube maintains its given color's integrity on all sides through the use of its complementary color when mixing the shadows.
This is such a powerful technique that will create a noticeable difference within your watercolor paintings.
Here's another example of using colors — not black — for shading to create form and shape in your watercolors.
This example comes from the class Startup Project: Watercolor Still Life with artist Mary P. Murphy and our partners Winsor & Newton.