Warm split-primary for interiors and still life
Interior painting lives or dies on whether shadows stay chromatic. A palette that mixes clean greens but produces grey shadows will make every room look like a photograph taken with the flash on. This one is built the other way round: greens are the hard part, shadows are the easy part.
Vermilion — Opaque, high-chroma orange-red.
| Pigment | Parts | Hex |
|---|---|---|
| Vermilion Hue | 3 : 9 (33%) | #C4472E |
| Cadmium Yellow Deep | 3 : 9 (33%) | #E0A32A |
| Cobalt Blue | 2 : 9 (22%) | #3B6FA8 |
| Indanthrene Blue | 1 : 9 (11%) | #2A3F6B |
Mixing notes
| Lamp light The warmest mix on the palette, used sparingly. More than a tenth of the panel becomes a sunset. | 4 cadmium yellow + 1 vermilion | #D98A34 |
| Sunlit wall Weak pigment load is what makes this read as a lit wall rather than as paint. | 3 cadmium yellow + 1 vermilion at 15% + 1 cobalt | #E3C48C |
| Shadow on skin A trace of indanthrene cools the shadow without turning it grey; without it the shadow looks like dirt. | 2 vermilion + 1 cobalt + a trace of indanthrene | #A9714F |
| Interior dark Equal parts warm and cool plus a blue anchor gives a dark that is still chromatic. | 2 cobalt + 2 vermilion + 2 indanthrene | #4A4038 |
- Set out the four pigments with the two blues separated by at least ten centimetres — vermilion and indanthrene contaminate each other quickly.
- Mix the lamp light and the sunlit wall first and paint them adjacent so you can see whether the value gap is one step or two.
- Mix the shadow-on-skin tone in three versions, at one part indanthrene, half a part, and none. Paint them in a row.
- Choose the version that reads as shadow rather than as a stain, and write that ratio down.
- Mix the interior dark last. It should look almost black in the well and dry to a warm, readable brown-grey.
- Test each mix on a scrap of the actual paper you will paint on. A palette card made on a different stock is not a reference.
- Store the card flat. Vermilion and the cadmiums are opaque and will crack if the card is rolled.
Two blues, and why the second one matters
Cobalt blue is a mid-value, slightly granulating, semi-opaque blue with a violet lean. Indanthrene blue is transparent, much deeper, and leans green. Together they cover the two jobs a shadow has to do: cobalt makes a shadow that still shows form, indanthrene makes a shadow that goes dark without going black.
Using only cobalt produces shadows that look washed out at the deepest point. Using only indanthrene produces shadows that swallow form entirely. The ratio is the tool.
Warm primaries need a value discipline
Vermilion hue and cadmium yellow deep are both opaque and both very high chroma. Mixed together at full strength they produce a colour that is brighter than anything in a real interior, which is why the working mixes dilute both to under 20% pigment load.
The exception is the focal point — a lamp, a piece of fruit, a lit edge. Keep one mix at full strength and use it on less than a tenth of the panel. That contrast is what makes the rest read as shadow rather than as under-painting.
Skin tones are the stress test
A skin shadow mix is three parts vermilion, one part cobalt and a variable trace of indanthrene. Without the indanthrene the shadow goes orange-brown and reads as dirt. With too much it goes purple and reads as bruise.
The useful range is roughly a quarter to half a part per three parts vermilion. Paint the three versions before you commit, because the difference between them is invisible in the well and obvious on the paper.
What matters
- Two blues with different jobs: cobalt keeps form, indanthrene deepens without blackening.
- Keep warm primaries under 20% pigment load except at the focal point.
- Skin shadow: 3 vermilion, 1 cobalt, and between a quarter and half a part of indanthrene.
- Make the palette card on the same paper you will paint on — a card on other stock is not a reference.
Handling note — Technique notes only. Cadmium pigments are heavy-metal compounds; follow the manufacturer's safety data sheet and never sand a dry cadmium passage without respiratory protection.