What color theory means for watercolor
Color theory is a set of ideas about how colors relate to each other: which ones sit well together, which ones contrast, and which ones make neutral grays and browns when mixed. In watercolor it matters a little more than in some other media, because the paint is transparent and hard to cover up. A muddy passage is difficult to repair, so it helps to understand your colors before you put them on the paper.
You do not need to memorize everything here. A working grasp of the wheel, color temperature, value and a few harmonies is enough to improve most paintings.
The color wheel
The color wheel arranges hues in a circle so that their relationships are easy to see.
- Primary colors are the starting hues that, in theory, cannot be made by mixing others. In the traditional system these are red, yellow and blue.
- Secondary colors are made by mixing two primaries: orange (red and yellow), green (yellow and blue) and violet (blue and red).
- Tertiary colors sit between a primary and a neighboring secondary, such as yellow-green or red-orange.
Many painters also work with a “modern” or split primary approach, using a cool and a warm version of each primary, or a cyan-leaning blue, a magenta-leaning red and a lemon yellow. These often give cleaner secondary mixes than a single traditional red, yellow and blue. Neither approach is wrong, and real paints never match the idealized wheel exactly. Painters in other media face the same issues; see oil painting color theory and mixing basics. For step-by-step practice, see our guide to mixing colors in watercolor.
Hue, value and saturation
Every color can be described in three ways.
- Hue is the color family itself: red, blue, green and so on.
- Value is how light or dark the color is. In watercolor, value is mostly controlled by how much water you add. See value in watercolor painting for how to plan it.
- Saturation (also called intensity or chroma) is how pure or dull a color is. A color straight from the tube is usually at its most saturated. Mixing in its complement, or a bit of gray or brown, lowers saturation.
You may also see the terms tint (a hue lightened with white or, in watercolor, with water), shade (darkened) and tone (dulled). Because watercolorists generally do not use white paint, tints come from diluting the pigment and letting the paper show through.
Warm and cool colors
Colors are often described as warm (reds, oranges, yellows) or cool (blues, greens, violets). Blues are the colors most commonly associated with cold, and blue-greens and blue-violets also read as cool.
Temperature is relative. Compare two reds and one will usually lean warmer, toward orange, while the other leans cooler, toward violet. The same is true of blues and yellows. Knowing which way a particular pigment leans helps you predict what it will do in a mix.
Temperature is also a tool for creating depth. Warm colors tend to feel closer and cool colors tend to recede, which is useful in landscapes and related to perspective in watercolor.
Color relationships that work
A few simple relationships can guide your palette choices.
- Analogous colors are neighbors on the wheel, such as yellow, yellow-green and green. Colors that sit next to each other are called analogous, and they usually give a calm, harmonious result.
- Complementary colors are opposites on the wheel, such as blue and orange, red and green, or yellow and violet. Side by side they make each other look more vivid. Mixed together they dull each other and produce neutrals.
- Triadic schemes use three colors spaced evenly around the wheel.
- Limited palettes use just a few pigments, which tends to make a painting feel unified and keeps mixing predictable.
A common approach is to let one temperature or one color family dominate the painting and use its opposite sparingly as an accent.
Paint your own color wheel
Making a wheel is one of the most useful beginner exercises.
- Choose a warm and a cool version of each primary, or just one of each if your palette is small.
- Draw a circle divided into twelve segments, or use small swatches arranged in a ring.
- Paint the three primaries in evenly spaced positions.
- Mix pairs of neighboring primaries to fill in the secondaries between them, then mix the tertiaries.
- Label the pigments you used. Add a note when a mix turned out duller than you expected.
Notice which secondaries look bright and which look gray. This tells you a lot about your specific paints.
Common color mistakes
- Overmixing many colors together, which tends to make mud. Try to use no more than two or three pigments in a mix.
- Ignoring value. A painting with good value structure can succeed even with imperfect colors, while the reverse is less often true.
- Using every color at full strength. Saturated color works best when it is surrounded by quieter areas.
- Not testing first. Try a mix on scrap paper, because watercolor dries lighter than it looks wet.
Where to go next
Once the basics are comfortable, practice mixing neutrals from complements and apply them to a real subject such as skin tones in watercolor. Pair color decisions with a layout plan using watercolor composition, and explore negative space painting to see how shapes and color work together.