Complementary colour pairs for oil painters

Complements sit opposite on the colour wheel and cancel each other towards grey. In practice some pairs neutralise cleanly and some make mud, because real pigments are not the pure hues on the diagram. These are the pairs worth learning, with the ratios that actually reach neutral.

The reliable pairs

Pair	Neutral near	Character
Ultramarine Blue × Burnt Sienna	2 : 1	The workhorse. Warm greys, cool browns, good darks without black.
Ultramarine Blue × Burnt Umber	1 : 1	Cooler, darker; a near-black for shadows.
Cobalt Blue × Cadmium Orange	3 : 1	Clean, luminous greys; orange is strong.
Alizarin Crimson × Viridian / Phthalo Green	6 : 1 or weaker	Rich chromatic greys and deep darks; the green dominates — dabs only.
Yellow Ochre × Dioxazine Purple	8 : 1	Soft warm neutrals; purple is extremely strong.
Cadmium Yellow × Ultramarine + a little red	—	Yellow has no single-tube complement; use violet or the two-tube version.

The ratios are starting points for one set of tubes. Tinting strength varies by brand — the same pair in Winton, Gamblin and Magicfly needs different amounts — so treat them as “which side dominates” rather than numbers to measure.

Pairs that make mud

Any pair where one pigment is far stronger than the other and you mix them in equal amounts: Phthalo Green with any red, Prussian Blue with orange, Dioxazine with yellow. The strong one wins, the mix goes dark and dirty, and adding white just makes it a dark pastel. Put the weak colour out first, add the strong one in dabs.

Complements made from earths (Burnt Sienna × Ultramarine) are forgiving because both are moderate tinters; complements made from modern organics (phthalo, quinacridone, dioxazine) are not.

Using complements for shadow colour

A shadow is the local colour darkened with its complement, not with black. Orange skin shadows get a dab of blue; green foliage shadows get red; yellow fabric shadows get violet. The shadow stays related to the object and the picture holds together.

Questions

What is the complement of blue in oil paint?

Orange. In practice Ultramarine Blue is neutralised by Burnt Sienna or Cadmium Orange; Cobalt Blue by Cadmium Orange.

Do complementary colours make black?

They make a very dark chromatic neutral, which is usually better than tube black in a painting. Ultramarine + Burnt Umber, or Alizarin + Phthalo Green, both reach near-black.

Why does my complement mix look muddy instead of grey?

One pigment is dominating or the value has dropped too far. Rebalance towards the weaker colour and lighten with white to see the hue.

Let the app do the arithmetic

PaintMixLab photographs the colour and writes the recipe in parts for the paint set you own. Free for 3 days on iPhone.