The Basics of Colour Theory

Colour theory can be a lot more complex than just learning about primary and secondary colours, but with the right tools and explanations, colour blending and colour coordinating can be easier and more intuitive than it appears at first glance.

Much of colour theory can be gleaned from looking at the world around and seeing what colours go together best, but when it comes to understanding colour palettes, colour blending, and the theories that go into which colours are warm and which are cold, which are saturated and which are desaturated, that’s when we start to require more detailed explanations.

So, to begin with the most basic terms, let’s go over primary, secondary, and tertiary colours.

Primary, Secondary & Tertiary Colours

​Primary colours are the most common introduction most people have to colour theory, though it is no shame at all if you have never heard of them before! The three primary colours – that is to say, colours that cannot be made by blending any other colours together and are fundamental to all other colours – are blue, yellow, and red.

Secondary colours are colours that can be created when any two primary colours are mixed together, which can be any shade of green, orange, or purple, depending on the ratio of each colour within the mixture.

Tertiary colours, to continue on, are colours that can be made by blending any combination of one secondary colour and one primary colour, like violet or yellowish green. There are also theoretically quaternary, quinary colours, and so and so forth, but at that point, we cease talking about distinct colours, and are now in the realm of discussing shades.

Colours of the Rainbow

Another way to organise this is the rainbow, where each primary colour flows into the next in all the shades between them – red, orange, yellow, green, blue, indigo, and violet, or ROYGBIV. This is the first of many acronyms we’ll run into in colour theory.

colours of the rainbow

When it comes to taking these primary colours and arranging them by a system, there are a few modes of thought.

The ROYGBIV rainbow method is the most natural, but there is also RGB, the additive method used most often for technology that depends on viewing all colours as lightwaves, as they exist in nature. The more colours you add, the brighter the light is to the human eye, with the basic colours being red, green, and blue, and the brightest intersection being white.

This is, however, much easier to understand when talking about screens, and isn’t very functional for painting and colour mixing in other mediums. To understand that method, we need to look at the colour wheel and the subtractive model. CMYK (cyan, magenta, yellow, and black) represents the subtractive theory of colour, where the more colour you add to a surface, the more light is subtracted from the surface and the darker the resulting pigment is to the human eye.

So, for example, if you were to add yellow to cyan, the resulting colour, a vivid green, would be darker than both. This is still abstract, and works better for printers than it does for painting by hand, so we shall move on to the colour wheel.

The Colour Wheel Theory for Colour Blending

The colour wheel theory, by far the most intuitive, takes the half circle of the rainbow and extends it out into a full circle, with the three primary colours (red, blue, yellow) acting almost as cardinal directions. Regardless of how you turn the colour wheel, each colour is surrounded on both sides by the two colour closest to it, and is directly across from the complimentary colour. So if you draw a straight line from, say, yellow, all the way across to the other side of the colour wheel, you’ll be met with that colour’s complimentary colour, in this case that colour being purple.

colour wheel theory
The Colour Wheel by insidemynest

Warm & Cool Colours

​Moving forward from this colour wheel theory of colour blending, we also have warm colours and cool colours. Dividing the colour wheel in half should give you two equal parts – yellow to maroon being the warm half, and purple to green being the cool half.

Choosing to use warm, energetic tones for an art piece gives the viewer a sense of motion, heat, and vivacious spirit. On the contrary, using cool tones exclusively may evoke calm emotions, or even provoke melancholy.

Hues, Shades, Tints & Tones

So, to continue on with the more detailed aspects of colour theory, we also have hues, shades, tints, and tones.

While in conversation, all of these words can be used interchangeably, they mean very different things when it comes to colour blending. Hues are used to talk about pure pigment, colours that are created by blending other colours and are their most vibrant form – often, this vibrancy is what we use to describe saturated colours.

Desaturated colours, however, can be referred to in the other three terms: when you add white to a colour, that is a tint; when you add grey to a colour, that is a tone; and when you add black to a colour, that is a shade. All of these generally tend to be more muted than the original colour, though that is not always the case.

Colours to which black has been added can just as often appear more vivid, though they tend to also be more subtle and hold greater depth. When you add grey in particular however, you always achieve a more muted and subtle form of the colour – compare, for example, pink (a tint which is achieved by adding white to red), maroon (a shade, which is created when a small amount of black to red) and pastel or champagne pink, a more muted and desaturated tone created by adding grey to red. 

There are many more elements to the art of colour blending, including the entire field of earth tones and playing with monochrome. However, with these basic elements of colour theory, the rest can best be learned by getting out there and practicing it yourself.