Primary Colours - Red, Blue, and Yellow
Probably the first lesson you ever learned about colour was that red, blue, and yellow are the primary colours. Every other colour is made up of some combination of these three.

When selecting curtains, you may not choose the bright boldness of a pure primary colour. But certain versions of the primary colours, like maroon, navy, or gold, can be the perfect choice for your home.

Secondary colours - Orange, Green, and Violet
Secondary colours lie between the primary colours on the colour wheel. These colours result from two primary colours being mixed together.

yellow red = orange
yellow blue = green
red blue = violet

Intermediate colours - The Remaining Six
Intermediate colours--also called Tertiary colours--result from one primary colour and one secondary colour being mixed together.

The six intermediate colours are: blue-violet; red-violet; red-orange; yellow-orange; yellow-green; and blue-green.

Neutrals--black, white, grey, and every variation in between--are not part of the colour wheel.

Those are the basics ... now for the mixing and matching that can simplify your curtain and fabric decisions.

Complementary colours
Colours that lie opposite each other on the wheel are complementary. The complementary colour for yellow, for example, is violet. For orange, it's blue. Pairing a colour with its complementary colour will make both colours more vibrant.

Analogous colours
Colours that lie beside each other on the colour wheel are analogous. They can be mixed without clashing because they share a common colour or hue.

Monochromatic colours
Each single colour on the colour wheel has a variety of shades. The colour violet, for example, can range from a deep eggplant to a light lavender. Using various tones of a single colour creates a monochromatic design.

Triad colours
A combination of three colours that are equally spaced on the colour wheel is known as a triad. These combinations can create a bold, yet balanced decorating palette.

Be cool. Or warm.
You'll often hear discussions about the relative temperature of a colour, whether it's cool or warm. The colour wheel tells you which.

Half of the colour wheel--from red to yellow-green--is considered warm. These colours appear as if they are advancing toward you, appearing nearer. They can help create a warm, cozy atmosphere.
The other half - from green to red-violet - is considered cool. These colours appear to recede, as though the space is expanding.

Green and violet may appear to advance or recede, depending on the colours used with them. So some interior designers consider them neutrals that can complement any colour scheme.

Can you mix warm and cool colours? Absolutely. In fact, a warm colour scheme often benefits from at least a hint of a cool colour to create balance. And a cool scheme may need a burst of warmth to liven it up.

The combination of warm and cool colours generally intensifies the relative temperature of each. One room featuring a predominantly warm colour next to a predominantly cool room can make the rooms seem more intensely warm or cool. Consider this effect when selecting your fabrics.

Other helpful definitions:
Hue: Another name for colour

Value: the lightness or darkness of a colour

Intensity: the brightness or dullness of a colour

Tint: colour + white, resulting in a lighter value

Tone: colour + grey, resulting in a darker value

Shade: colour + black, delivering the darkest versions of colour