1)  Direct Harmony: This is the most basic harmony. It is a point opposite to the key colour on the wheel.  This “opposite” colour is referred to as the complementary colour and thus the direct harmony can also be called the complementary harmony. Virtually all colour harmonies (except Analogous) are a variation of the direct harmony.

The high contrast of complementary colours creates a vibrant look especially when used at full saturation but can be jarring if not managed properly. This is the most common colour scheme and is easy to find in all sorts of designs.

Complementary colour schemes are tricky to use in large doses, but work well when you want something to stand out. Complementary colours are really bad for text as both colors have a similar “strength” and will fight for attention.

2) Split Complementary: Rather than the point opposite the key colour on the wheel, the split complementary takes the two colours directly on either side of the complementary colour. This allows for a nicer range of colours while still not deviating from the basic harmony between the key colour and the complementary colour.

This colour scheme has the same strong visual contrast as the complementary colour scheme, but has less tension.  The split complimentary colour scheme is a safe choice for virtually any design as it is near impossible to mess up and always looks good.

3) Triadic Harmony: This refers to the colour two spaces to either side of the key colour’s complement. Essentially, with the triadic harmony, you are using three equally distanced colours on the colour wheel. This harmony is best used with only touches of colour.

Too much of each colour and a design will appear to have too many colours and can be too vibrant.

To use a triadic harmony successfully, the colours should be carefully balanced—let one colour dominate and use the two others for accent. Or, desaturate all colours and only use the triadic colours in small spots or touches.

4) Analogous Harmony: Also referred to as related colours, these are the colours directly on the left and right of your key colour. They usually match up quite well and create a serene and comfortable design. While this colour harmony can be pleasing to the eye, it can also come across as monotone. If  going for a design that’s primarily one colour, this is a good choice.

5) Tetradic Harmony: Similar to the Triadic, except that there are four points, all equally distanced on the colour wheel. It is a design simply using two sets of complementary colours.This harmony is good when you have numerous elements that all need to stand out on their own—such as a poster that features 4 or more characters. By using colours equally distant on the colour wheel, each character gets equal attention.