Color theory in practice: harmony, contrast, and meaning.

Colour is one of the media designer's most powerful tools. It controls what the eye is drawn to, sets mood and can signal danger, calm, quality or play before a single word is read. But colour chosen on intuition alone often ends up muddled. A basic understanding of colour theory makes your choices conscious and explainable.

The colour wheel organises colours so you can see their relationships to each other. Each colour can be described with three properties: hue (which colour it is), saturation (how pure or greyish the colour is) and lightness (how light or dark it is). When you adjust a colour, it is almost always one of these three you change.

A colour scheme often becomes calmer if the colours have a conscious relationship to each other in the colour wheel. A few classic approaches will help you get started:

• 01Complementary: two colours opposite each other in the circle — great contrast and energy.
• 02Analog: colors that are next to each other – harmonious and calm.
• 03Triad: three colors evenly distributed in circle — lively but balanced
• 04Monochrome: one hue in different values and saturations — very coherent.

Contrast is not just dark against light. You can create contrast with colour, saturation, brightness, size and warmth/coolness. The most important contrast in most designs is between text and background: if it is too low, the text becomes difficult to read, regardless of how nice the colour scheme is.

Some users have reduced colour vision or read on poor screens and in poor light. Colour must therefore never be the only carrier of a message — also use shape, text or icons. And ensure sufficient lightness contrast between text and background so content can be read by as many as possible. There are recognized guidelines for accessible contrast that you should test your choices against.

Colors don't mean the same everywhere. A color that signals party in one context can signal warning in another, and meanings vary between cultures and industries. Always think about who's seeing the design and in what context — target audience and context are at least as important as the color wheel.

“Don't choose a colour because you like it — choose it because it does what the message needs.”

— Basic principle in applied colour theory