A lesson about matching the tonal values of colours

I was recently asked to write an article for an online magazine. Being fanatical about colour matching made it an easy decision to write about one of my favourite colour matching games. 

So here's the article:

Understanding the tonal values of colours

It’s a good idea to practice colour matching for its own sake to improve accuracy and harmony in your paintings.

It’s also a good idea to match the most prominent colours in a scene before you begin to paint it. Mixing colours before you begin to paint allows you to focus exclusively on the colour and tonal value relationships. You don’t have to worry about drawing, shapes, brushwork, surface or expression at this stage. By focussing solely on the colours for a few minutes before you begin, you can allow yourself to concentrate on capturing the sense of light and the essence of the day through the temperature and balance of the colours. It can be a very satisfying process and is often one of my favourite stages in making a painting. In fact, it’s a great exercise in its own right and I recommend it as a way to use up spare paint at the end of a day, or to use up a few minutes at the end of a session. The method outlined below has improved the speed and accuracy of my colour matching more quickly than any other exercise – and its great fun too!

I always begin by playing a game of pairs. I look at the scene before me and try to guess which colours would share the same tonal value a black and white photo. I try to identify which are the ‘darks’ and which are the ‘lights’. Everything else will be a mid-value. Squinting helps me to see similarities in the tonal values of the colours, it simplifies the value pattern, allowing dark areas to merge and middle values to become more apparent.

  Try to guess which parts of the picture will be the same shade of grey in a black and white photo

Try to guess which parts of the picture will be the same shade of grey in a black and white photo

Then I photograph the scene and use my smartphone to turn the image into black and white; I check to see how accurate my guesses were.

  Notice how the red and turquoise buildings have a very similar tonal value to the blue sky and the tarmac whilst the green and orange buildings at the end of the road also make a value pair.

Notice how the red and turquoise buildings have a very similar tonal value to the blue sky and the tarmac whilst the green and orange buildings at the end of the road also make a value pair.

As I begin to match the colours from the scene on my palette, I remain aware of their tonal value. I mix all my ‘darks’ adjacent to one another, so that I can squint at my palette and assess whether they are of a similar value. I do the same with the mid-value colours, and with the lights; the various piles of colour on my palette are arranged in bands of values from light to dark.

  Notice how the colours run from light to dark across the palette.

Notice how the colours run from light to dark across the palette.

Once the colours are mixed on my palette, I take a photograph of them and turn it into black and white. This shows me how accurate my value perception really is, I can tell if one of my colours is lighter or darker than it should be, and I can fix it before I begin to paint with it!

  In greyscale it is much easier to see the difference in tonal value from one colour to another. The palette is arranged with 5 distinct value bands running from left to right.

In greyscale it is much easier to see the difference in tonal value from one colour to another. The palette is arranged with 5 distinct value bands running from left to right.

This exercise can be done on location and in your studio, it is the best way to simultaneously develop your tonal value perception and your colour mixing skills in a fun, enjoyable challenge.

Matching the colours before you paint on location has another great benefit for which I have often been grateful; if the weather suddenly changes, or the boat you are painting sails away, you already have all the information you need to complete a painting in your studio! If you have an accurate colour match from the scene, and a decent photo to illustrate the shapes and relative tonal values, you can finish the work at a later date. If I’m out painting and I see something I really want to paint, but I don’t have time to complete a painting on the spot, I often make a quick colour match and snap a photo as reference for later. The colour swatches matched on location can then be used back in the studio in conjunction with photos to make a finished painting.