Clean violet
ΔE 1.4- 5 parts Ultramarine Blue
- 3 parts Titanium White
- 2 parts Alizarin Crimson strong tinter
Target beside the rounded-parts mix; in mixing order, strongest pigment last. Below a trained eye’s threshold.
Limited palette, mapped
The Split-primary palette: what it can mix and what it can’t
The mixable gamut of the Split-primary oil palette, computed tube by tube with Kubelka–Munk pigment physics. Colours shown at full strength are reachable by some mix of the tubes. The dimmed region is out of reach at any ratio.
See this gamut in Halftint
The same wheel, computed for the tubes you own. Free.
Same palette, three values. Coverage is the share of the hue/saturation disc within ΔE 3 of a physically mixable colour, on the same engine and threshold the app uses. Tube colours are chart-derived and labelled approximate; see the method page.
The tubes
- Titanium White
- Cadmium Yellow Light
- Cadmium Yellow Deep
- Cadmium Red Light
- Alizarin Crimson
- Ultramarine Blue
- Phthalo Blue (GS)
A warm and a cool of each primary (two cadmium yellows, cadmium red light beside alizarin crimson, ultramarine beside phthalo blue) plus titanium white. The split-primary palette is the standard answer to “which six tubes should I buy?”, and the computed wheels above show why. It holds the widest territory of the classic teaching palettes, because every secondary can be mixed from the pair that leans towards it.
It is still a territory with borders. Pigment mixing is subtractive, so every mix trades away some chroma, and the most saturated notes between the primaries stay out of reach at any ratio. The dimmed ring near the wheel’s rim is the limit of what six tubes and white can do.
What it cannot reach
The gaps cluster where mixing costs the most chroma: the cyan-turquoise arc and the electric violets. Here is each popular target, the closest the palette gets, and the single tube that closes the gap.
| Target | Target vs closest mix | Gap | One tube that closes it |
|---|---|---|---|
| Saturated cyan | ΔE 8.2 | Cerulean Blue → ΔE 4.6 | |
| Vivid spring green | ΔE 9.3 | Cerulean Blue → ΔE 5.2 | |
| Electric violet | ΔE 16.7 | Permanent Rose (Quin.) → ΔE 12.4 | |
| Hot magenta | ΔE 12 | Permanent Rose (Quin.) → ΔE 3.7 | |
| Saturated turquoise | ΔE 8.9 | Cerulean Blue → ΔE 3.7 |
Every number is computed with the same engine the app runs: the closest mix the Split-primary tubes can make, how far it falls short, and the single tube (from the generic single-pigment range) that best closes the gap.
Signature mixes, in knife-parts
Inside the borders the palette earns its reputation. Computed knife-part recipes for the classic student problems. Note how the warm and cool pairs get chosen for you by the maths.
Summer foliage green
ΔE 3.7- 3 parts Cadmium Yellow Deep
- 2 parts Cadmium Yellow Light
- 2 parts Cadmium Red Light
- 3 parts Phthalo Blue (GS) strong tinter
Target beside the rounded-parts mix; in mixing order, strongest pigment last. Reads as a match in a painting.
Sky blue tint
ΔE 1- 10 parts Titanium White
- 3 parts Ultramarine Blue
- 2 parts Phthalo Blue (GS) strong tinter
Target beside the rounded-parts mix; in mixing order, strongest pigment last. Below a trained eye’s threshold.
Warm neutral grey
ΔE 3.8- 5 parts Titanium White
- 5 parts Ultramarine Blue
- 4 parts Cadmium Yellow Light
- 2 parts Alizarin Crimson strong tinter
Target beside the rounded-parts mix; in mixing order, strongest pigment last. Reads as a match in a painting.
Against the alternatives
The limited-palette debate is a gamut argument, so compare gamuts. Same engine, same mid value:
Keep exploring
Now draw the map for your own palette
Load the tubes you own, from the brand lists or as custom entries by pigment code, and Halftint computes your range, with knife-part recipes for everything inside it and the ΔE for everything that isn’t.
Open Halftint