Why does everyone say value matters more than colour?

The eye has far more receptors for light and dark than for colour, and they are distributed differently and used differently. Practically, that means your visual system reads shape, depth and light from value and reads colour as a secondary layer of information on top. Painters discovered this centuries before anyone could explain it, which is why the advice is so consistent.

Step by step

1. Separate the two ideas properly.Hue is the name of the colour — red, blue-green. Value is how light or dark it is on a scale from white to black. Saturation is how intense or how greyed it is. They vary independently, and confusing value with saturation is the root of most colour problems.
2. Learn the value of your pure colours.Straight from the tube, yellow is very light — around a 2 on a nine-step scale. Pure red is much darker, often around a 6. Ultramarine is darker still. This surprises people constantly, and it explains why a bright yellow highlight works and a bright red one does not.
3. Check every painting in greyscale.Photograph it on your phone and switch the image to black and white. If everything collapses to a similar grey, the picture has no value structure, and no adjustment of hue will fix it.
4. Do a value study before painting.A small monochrome sketch — pencil, or one colour thinned to several strengths — settles the whole composition in ten minutes. Almost every painting that fails structurally would have been caught here.
5. Group the picture into three or four values.A big light mass, a big dark mass and a mid tone, arranged in a shape you find interesting, is what makes a painting read from across a room. Scattered values of similar strength read as noise.
6. Adjust value with a related colour, not with black or white.Darkening with black kills the hue. Darken a red with a violet or a deep brown; darken a green with a dark blue. Lighten a colour with a lighter colour of similar hue rather than reaching straight for white, which desaturates fast.
7. Use saturation as a separate control.Once the values are right, the saturation decides where the eye goes. A picture that is mostly muted with one saturated passage will direct attention exactly where you want it. Everything saturated is exhausting and directs attention nowhere.
8. Match value first when you cannot get a colour right.If a mixed colour looks wrong, squint at it against the target. Nine times out of ten it is the value that is off rather than the hue, and correcting the value makes the hue look right without touching it.

Tips

• A red filter or a piece of red acetate held over a scene removes most hue information and shows you value directly. Old-fashioned and still effective.
• Photographing your reference and your painting in the same greyscale conversion lets you compare them properly, which is far more informative than comparing colours.
• Painting a whole picture in one colour plus white — a monochrome study — is one of the fastest ways to improve, and it removes every excuse.
• This is the same principle that makes a black-and-white photograph work. Nothing is lost structurally when colour is removed, which tells you how much of the load value was carrying.

Common mistakes

• Reading a saturated colour as light because it is bright — Brightness in the sense of vividness is saturation, not value. A pure saturated red is a middle-dark value. Treating it as a light is why so many paintings have a hole in them.
• Fixing a failing painting by adjusting the colours — If the greyscale version is mush, the colours are not the problem and changing them cannot help. Separate the light masses from the dark ones instead.
• Using white to lighten everything — Adding white lightens and desaturates simultaneously, so a picture lightened with white goes chalky and pale. Use a lighter hue where you can.

Questions people ask