Color Theory Basics
Color theory is the set of principles designers use to combine colors in ways that feel intentional. You do not need to memorize rules to benefit from it; understanding a few core ideas — the color wheel, the three properties of a color, and how colors relate — is enough to make confident choices. This guide covers those fundamentals and points to tools that let you apply them immediately.
The color wheel
The color wheel arranges hues in a circle so their relationships are easy to see. Primary colors sit evenly around it, with secondary and tertiary colors between them. When you rotate around the wheel, you move through the full range of hues, which is exactly what harmony tools do when they calculate complementary, analogous, or triadic sets.
Hue, saturation, and value
Every color can be described by three properties. Hue is the color family, such as red or blue, measured as an angle on the wheel. Saturation is how vivid or muted the color is. Value (or lightness) is how light or dark it is. The HSL and HSV formats map directly to these properties, which is why they are so useful when adjusting a color deliberately.
Changing one property at a time is a reliable way to build a coherent palette: keep the hue and vary lightness for a monochromatic scale, or keep lightness and shift hue for a set of equally bright accents.
Warm and cool colors
Colors are often grouped into warm (reds, oranges, yellows) and cool (greens, blues, purples). Warm colors tend to feel energetic and advance toward the viewer, while cool colors feel calm and recede. Balancing warm and cool tones, or committing to one, is a quick way to set a mood.