Ask what colours make brown and you get a dozen answers: red and green, blue and orange, all three primaries, purple and yellow. They are all right, and they are all the same answer. Brown is a dark, dull orange. Any mix that lands on the orange side of the wheel and then loses most of its chroma is brown. The pairs people quote are just different ways of doing that.
Why red and green make brown
Red and green sit roughly opposite each other, so mixing them cancels chroma. Pigment mixing is subtractive: each paint absorbs part of the spectrum, and the mix absorbs everything either one absorbs. Cadmium red absorbs the blue and green wavelengths, viridian absorbs the red ones, and what survives is a dim band in the yellow-orange region. The result is a low-chroma orange, which is to say brown. Mixed with the engine behind Halftint, equal amounts of cadmium red light and viridian come out as
- cadmium red light + viridian, 1:1
- cadmium red light + permanent green light, 1:1
The earth colours are browns already
Burnt sienna, burnt umber and raw umber are brown out of the tube because the iron oxide pigments in them are, by nature, dull dark oranges. If you own them, the fastest brown is not a mix at all. The interesting question is which brown, and that is where recipes help.
Five browns, three palettes
The recipes below were computed with Halftint's Kubelka–Munk engine for three standard palettes: a split-primary set (two cadmium yellows, cadmium red light, alizarin, ultramarine, phthalo blue, white), an Impressionist set (no black, viridian instead of a second blue), and an earth set (ochre, siennas, umbers, black, white). Parts are knife-loads. The number on each card is how far the rounded parts land from the target in OKLab units times 100; under 3 reads as a match.
Chocolate brown
Split-primary palette
ΔE 1.3- 5 parts Cadmium Red Light
- 3 parts Cadmium Yellow Deep
- 3 parts Alizarin Crimson strong tinter
- 3 parts Phthalo Blue (GS) strong tinter
Target on the left, the colour these parts make on the right. Add in the order listed, strongest pigment last.
Impressionist palette
ΔE 0.5- 6 parts Viridian
- 7 parts Cadmium Red Light
- 3 parts Alizarin Crimson strong tinter
Target on the left, the colour these parts make on the right. Add in the order listed, strongest pigment last.
Earth palette
ΔE 1.1- 3 parts Raw Sienna
- 6 parts Burnt Sienna
- 2 parts Yellow Ochre
- 4 parts Ivory Black
Target on the left, the colour these parts make on the right. Add in the order listed, strongest pigment last.
Note how the split-primary version is built: red and yellow for the orange, then alizarin and phthalo blue to darken and dull it. That is the red-and-green rule with the green assembled from its parts.
Warm mid brown
Split-primary palette
ΔE 1.7- 4 parts Cadmium Red Light
- 3 parts Cadmium Yellow Deep
- 2 parts Cadmium Yellow Light
- 3 parts Alizarin Crimson strong tinter
- 2 parts Phthalo Blue (GS) strong tinter
Target on the left, the colour these parts make on the right. Add in the order listed, strongest pigment last.
Impressionist palette
ΔE 0.8- 3 parts Viridian
- 5 parts Cadmium Red Light
- 2 parts Cadmium Yellow Light
- 2 parts Alizarin Crimson strong tinter
Target on the left, the colour these parts make on the right. Add in the order listed, strongest pigment last.
Earth palette
ΔE 1.5- 2 parts Raw Sienna
- 5 parts Burnt Sienna
- 2 parts Yellow Ochre
- 1 part Titanium White
- 2 parts Ivory Black
Target on the left, the colour these parts make on the right. Add in the order listed, strongest pigment last.
Tan
Split-primary palette
ΔE 2.5- 3 parts Cadmium Red Light
- 2 parts Cadmium Yellow Deep
- 2 parts Cadmium Yellow Light
- 2 parts Titanium White
- 1 part Phthalo Blue (GS) strong tinter
Target on the left, the colour these parts make on the right. Add in the order listed, strongest pigment last.
Impressionist palette
ΔE 1.4- 5 parts Cadmium Red Light
- 4 parts Cadmium Yellow Light
- 4 parts Titanium White
- 4 parts Ultramarine Blue
Target on the left, the colour these parts make on the right. Add in the order listed, strongest pigment last.
Earth palette
ΔE 3- 2 parts Raw Sienna
- 2 parts Burnt Umber
- 2 parts Yellow Ochre
- 1 part Titanium White
Target on the left, the colour these parts make on the right. Add in the order listed, strongest pigment last.
Tan is the hardest of the five for every palette, and the reason is worth knowing. It is a pale brown, so it needs white, and white lightens without removing chroma. The mix has to be dulled first and lightened second, or it comes out as a pale orange. Halftint puts the white early in these recipes because white is the weakest tinter, but the desaturating paint is doing the real work.
Taupe, a grey-brown
Split-primary palette
ΔE 3.9- 2 parts Titanium White
- 2 parts Cadmium Yellow Light
- 1 part Cadmium Yellow Deep
- 4 parts Ultramarine Blue
- 2 parts Alizarin Crimson strong tinter
Target on the left, the colour these parts make on the right. Add in the order listed, strongest pigment last.
Impressionist palette
ΔE 1.8- 3 parts Titanium White
- 3 parts Cadmium Yellow Light
- 1 part Cadmium Red Light
- 5 parts Ultramarine Blue
- 2 parts Alizarin Crimson strong tinter
Target on the left, the colour these parts make on the right. Add in the order listed, strongest pigment last.
Earth palette
ΔE 2.1- 3 parts Yellow Ochre
- 3 parts Titanium White
- 5 parts Ivory Black
Target on the left, the colour these parts make on the right. Add in the order listed, strongest pigment last.
Taupe sits so close to grey that the blue leads the recipe. It is brown only in the sense of leaning slightly warm.
Red-brown
Split-primary palette
ΔE 0.7- 3 parts Cadmium Red Light
- 2 parts Cadmium Yellow Deep
- 3 parts Ultramarine Blue
- 2 parts Alizarin Crimson strong tinter
Target on the left, the colour these parts make on the right. Add in the order listed, strongest pigment last.
Impressionist palette
ΔE 0.5- 2 parts Viridian
- 3 parts Cadmium Red Light
- 1 part Cadmium Yellow Light
- 2 parts Alizarin Crimson strong tinter
Target on the left, the colour these parts make on the right. Add in the order listed, strongest pigment last.
Earth palette
ΔE 1.5- 6 parts Burnt Sienna
- 5 parts Burnt Umber
- 3 parts Yellow Ochre
Target on the left, the colour these parts make on the right. Add in the order listed, strongest pigment last.
Getting the brown in front of you
Every brown you will ever need is one of these with a nudge. Too orange: a speck more of the blue or the green. Too grey: a speck more of the red. Too dark: white, but expect it to lift the chroma at the same time, so follow with a trace of the complement. Too light: the darkest earth you own, not black, which cools everything.
If you want the recipe for a particular brown from the tubes you actually own, that is what Halftint does: pick the colour, or sample it from a photo, and it computes the knife-parts and the order for your palette.