How to Choose Colors for a Painting from a Photo

Find the 5 to 8 big color masses in the photo, judge the value of each, correct for what the camera changed, and mix those before anything else. Most of the painting will be small variations on them.

Decide the light and the extremes

George Clausen, teaching at the Royal Academy in 1904, described how to start a color study from nature: settle the general tone of the whole, warm or cold, then the highest light and the darkest dark, and only then work in detail. It works the same from a photo. Before you mix anything, decide:

• whether the light is warm or cool (see warm and cool colors);
• which mass is the lightest, and which the darkest.

Every other color in the painting sits between those two values.

Find the big masses

A mass is an area you could paint as one color to begin with: the sky, the far hills, the sunlit grass, the grass in shadow, an animal's coat. Harold Speed called reducing a complicated scene to a few simple masses the painter's first necessity. Squint at the photo or blur it so the small variations merge (see why painters squint), and name the masses that are left. Aim for 5 to 8. If you count 15, you're still seeing detail.

The palette from a photo tool does this grouping for you. It sorts the photo's colors into a set number of masses, 8 unless you change it, and shows each one's share of the picture. Tap a color to see everywhere it appears. If one color covers two areas you'd paint differently, such as shadow on grass and shadow on rock, raise the number of colors by one or two.

Judge the value of each

Get the value right before the hue: a color at the wrong value breaks the form however good its hue (see value and color). The tool gives each color's value on a 0 to 10 scale and can order them from dark to light. Compare that order with a value study of the same photo in the notan and value study maker. If two masses come out at the same value, such as a dark coat against dark shadowed grass, decide now whether they should merge in the painting or be pulled apart.

Correct for the camera

Two settings change a photo's colors before you see them.

• Exposure. In a high-contrast scene, one exposure can't keep detail in both the lights and the darks, so the shadows go black or the sky goes white. Cameras get around this by combining exposures: an iPhone takes several in quick succession and blends them to bring out more highlight and shadow detail. The shadows in a phone photo can then be lighter and busier than they looked. Judge the darkest dark against what you saw, or against a second photo exposed for the shadows.
• White balance. The camera shifts colors so they look natural under whatever light there was, and some cameras have a setting just to remove the warm cast of lamplight. Warm evening light and the blue of shade can come out more neutral than they were. If you remember the light as warm, push the palette warmer. On a clear day, shadows lit by the sky lean blue even when the photo shows them gray.

Mix the masses

1. Start with the largest mass. Every other mix is judged against it.
2. Mix to the value first, then adjust the hue, then the chroma. To make a color duller, add a little of its complement or a gray of the same value. Black dulls some colors and shifts others: black and yellow make an olive green.
3. Judge each new mix on the canvas, next to the mass beside it. Colors change with their neighbors, so a mix that matched the swatch on its own can look wrong in place.
4. Use the hex code as a target to compare against, not a recipe. Paint doesn't mix like light on a screen.

A limited palette keeps the mixing simple: a few tubes, often a warm and a cool version of each primary plus white. Winsor & Newton suggest the warmest and coolest of the three primaries in a range as a starting point. When every color is mixed from the same few tubes, the colors stay related to each other.

Sources

• George Clausen, Six Lectures on Painting, Methuen, 1904, lecture III, "On Colour": deciding the general tone, the highest light and the darkest dark before working in detail. Project Gutenberg.
• Harold Speed, The Practice and Science of Drawing, 1913, chapter V, "Mass Drawing": reducing a complicated appearance to a few simple masses. Project Gutenberg.
• Apple, "Adjust HDR camera settings on iPhone", iPhone User Guide: several photos at different exposures, blended for more highlight and shadow detail.
• Nikon, "HDR Overlay", Nikon Z f Reference Guide: combining two exposures to keep detail in the highlights and shadows of high-contrast subjects.
• Nikon, "White Balance", Nikon Z f Reference Guide: white balance makes colors look natural whatever the light source, and one setting removes the warm cast of incandescent light.
• Christopher S. Baird, West Texas A&M University, "Why doesn't the outside world appear blue even though so much light comes from the blue sky?", 2014: shadows on a clear day are lit by blue skylight.
• Winsor & Newton, "Is there a list of warm and cool colours for each of the Winsor & Newton colour ranges?": the warmest and coolest primaries as a starting palette.