Colour: Value, Chroma and Temperature

Colour is a major part of most paintings. So how do you choose your paint colours and how do you mix and combine them? Can you and should you aim to copy the exact colour of your subject? What does chroma mean and how important is value? Colour theory is a huge topic and many books are written about it.  In this post I just want to point you to the most useful traits of colour you can use while you paint. 

When looking at the colour of something it can really help to focus on four things: hue, chroma, value, temperature.

Although heavy tomes have been written on any of these subjects I want to keep it simple here and just show you some basics. Without needing a Ph.D on colour theory these little pointers prove very handy in my daily painting life and so I want to share them with you.

Hue

Hue is a word that has caused many debates about its meaning. Hue and tone can be confusing but I do not think that it is always very helpful to get lost in theoretical debates when you just want to paint. So for argument's sake hue just means which colour you are using. Grass is green, my trousers are blue and the poppy is red. The hue is simply which colour family a thing is. We usually do not need to think long and hard about this one. 

Chroma

Then there is Chroma. I find this concept really very helpful. Chroma refers to the purity and depth of a colour. It tells you how 'colourful' something is or how saturated. So if you are looking at an orange tulip, for example, you can help your painterly eye but trying to find where the orange is the most orange. A high chroma colour is where the red is the reddest, the blue the bluest etc. A high chroma colour is where a colour is at its most pure, where it is not muddled by whites, blacks or other colours. 

I find it really useful to find these strong colour areas in any subject matter I am painting. But it also pays off to judge any colour area on its chroma individually. Many colours are of a much lower chroma than the purest colour. They are greyed down, neutralised or they take on other colours from its surroundings. 

When you look at any area in your painting subject, have a think and figure out how high or low the chroma of that colour is. Then adjust your paint choices accordingly. 

A area of skin colour in a portrait, for example, can be very low in chroma. Skin is generally not high in chroma or colour. In skin colour is often a little greyed out, muted and soft. But if a golden sunset is illuminating the skin, or a coloured spot light, we could get some real dense spots of colour appearing! 

Temperature is another super useful concept when you are trying to figure out what colour to paint something. The temperature of a colour is either warm, cool or neutral (in between). Generally speaking a warm colour tends to have reddish tones while a cool colour has blueish tones in them. Most people would agree that red is 'warm' and blue is ‘cool'.

When you look at a small shape within the subject of your painting you can again try and judge the temperature of it. But you can only judge it in relation to the rest of the painting or subject. Do not judge the temperature of a colour on its own. After all a neutral yellow might well be the warmest colour in a sea of grey blue, yet that same neutral yellow can be a cool  colour if it is surrounded by hot reds and oranges!

So a colour is either warmer or cooler than the other colours in your subject. It is never just 'warm' or 'cool' on its own.

Use it when you are painting

click here to read more about this pastel portrait

For example, if we look at a small area on the cheek of your model, you might just see a lovely skin colour. But how to paint this skin colour? 

• Temperature. Firstly you can try and figure out whether the skin colour of the cheek is warmer or cooler than the skin colour of the other cheek (often the two cheeks of a model have a different lighting, separated by the nose). 
• Value. You can also try and see (this is often a little easier) whether it is lighter or darker than the other cheek.
• Chroma. Try and see how chromatic the colour is. Does it have a higher chroma than the other cheek or is it more greyed out and dull? 
• Hue. You have probably already established the hue, or the main colour family of this cheek. It is probably a greyish pink or a yellowish green, or a brownish red, or a .... It doesn't really matter what you call it really. 

Applying all  these concept to an area of colour really helps in figuring out how to paint it.

Another final example: if you want to paint that red poppy you will want to not just grab some red paint and simply colour in the petals. You need to find the variety in light, temperature, value and chroma. Is that left petal more muted than that little lip of that right petal? Is there a slight light reflection hitting that lower area on the outer petal making it lighter than the top area? Is that little lighter bit warmer or cooler than its surroundings? If you are stuck on how to paint a certain colour within your painting then asking yourself these questions might help you getting it right. 

Tulip Photo by sergee bee on Unsplash