A beginners guide to the language of colour theory

Learning colour theory means learning the language that goes along with colour. Understanding what each term means can make it easier to follow what various artists mean when they talk about the colours they’re using. 

I’ll share the meaning of several words but it’s important to understand that some words are consistently accepted in colour theory, while others might be defined differently. As with anything related to colour theory, the language of colour isn’t universal. I’m also approaching this from the perspective of an acrylic painter. The information is useful for any physical art media, like paints.

Watch me share the language of colour on my Youtube channel.

The basics

Let’s start with a couple terms that will help us understand the complexity of the language of colour:

Colour: what exactly is colour? It’s the combination of pigments, lighting, our perception, and more. It seems so simple – a colour is colour, of course! But the more you learn, the more you understand that the world of colour is complex.

Relative – our perception of colour depends on what a colour is next to or being compared against. Colour is heavily influenced by lighting and surrounding colours. For example, place a grey colour next to a dark colour and the grey will seem lighter. Now put the same grey next to a light colour, and it’ll seem darker. As you learn about colour, you’ll find many aspects of colour are relative. 

Properties of colour

The big three terms can help simplify the complexity of understanding colour. Hue, chroma  and value are very common terms to help artists define a specific colour. 

Hue – simply put, it means a colour family. Red is a hue. Blue is another hue. Let’s use red as an example. Quite a few different colours are red. Think of quinacridone magenta and cadmium red. They’re both pretty different, but they’re both considered red hues because they’re part of the red “family” of colours. 

Chroma – the intensity or purity of a colour. A pure colour is when it’s most highly chromatic. Keep in mind that a pure colour isn’t necessarily high chroma. A yellow ochre is not high chroma even when it’s straight out of the tube. A lemon yellow is high chroma though. Add grey or a complementary colour to either, and you can lower the intensity of either colour. 

Some people use the term saturation instead of chroma. There is a difference between the two – saturation is often used related to light while chroma is for physical paint. I often use them interchangeably as well because of my first career in television broadcasting. 

Value – the lightness or darkness of a colour. The value of a colour is often compared using a value scale, which usually has 9 or 10 steps from black to white. Think about taking a photo with your phone, then turning it to a black and white photo. You can clearly see the value of different colours. 

Some pure colours naturally have a light value, such as yellow, while purple is generally very dark. You can adjust a colour’s value by mixing with other colours, or black or white paint. 

Refining how we describe a colour

The next two words help to define a colour with greater precision. They are closely related and, in some cases, are used interchangeably (e.g. a warm yellow is a red-yellow). 

Temperature – whether a colour is warm or cool. Generally speaking, green, blue and purple are considered cool colours, while red, orange and yellow are considered warm. When painting, you’ll often want to use cool colours in shadows and warm colours for where light is hitting the object or scene.  

Colour temperature is relative. Take blue as an example. Blue is generally considered a cool colour. But when ultramarine blue and cerulean blue are next to each other, ultramarine blue is warm, while cerulean blue is cool. Now put purple next to ultramarine blue. The purple is now warm since it’s closer to red while the ultramarine blue is now considered cool. 

Bias – the direction a colour “leans” on the colour wheel. Take a yellow paint. Since yellow is in between green and red on the colour wheel, yellow can be green-biased or red biased. A lemon yellow is a green-yellow, because it’s closer to green on the colour wheel and it inherently has some green in it. A cadmium yellow deep is a red-yellow, since it’s closer to red on the colour wheel. 

If you want to master colour mixing, you’ll need to understand colour bias. When you can identify the colour bias, it will ensure you mix the colour you actually want. If you want a vibrant green, use a yellow with a green bias (a green-yellow), such as lemon yellow, and a blue with a green bias (a green-blue), such as phthalo blue (green shade). 

Traditional colour wheel colours

There are several types of colours, which can be modelled on a traditional colour wheel for painters.

Primary colours – just like when you were a kid, the primary colours are red, blue and yellow. These three primary colours can be used to mix any hue.

Secondary colours – the colours you can mix with two primaries. Unlike when we were kids, now that you’re learning colour theory, you’ll learn that it’s more complicated. While you can use  red and yellow to create an orange, you can’t create any orange. Learning more about colour theory and understanding the pigments in paint will help you mix a wider, and more predictable, range of colours. 

Tertiary colours – when you mix a primary and secondary, you get a tertiary colour. Turquoise is a tertiary because it’s a mix of green and blue. 

Complementary colours – two  colours opposite on a colour wheel. When you mix two complementary colours, you get black. Complementary colours also tend to have a high contrast or vibrancy when next to each other. Red and green are complementaries. 

Go more in depth on these terms in my blog post on making your own colour wheel.

Final words

This section is titled final words, but this blog post is just the beginning. There is an incredible depth and breadth to colour theory, including the different terminology. Subscribe to my YouTube channel or visit my blog to learn more about colour theory and colour mixing with acrylic paints.