Warm undertone
Skin above 62° of hue — golden or peach beneath the surface, with the redness to match.
Also called golden, yellow-toned, peach.
Measure your own undertoneWhat it means
Golden, peach or yellow beneath the surface, at a clearly warm hue angle with the redness to match.
Undertone is a hue angle, measured in the CIE Lab colour space. Every human complexion falls in a narrow band between roughly 45° and 75° — all skin is some version of orange, and the only question is where inside that band yours sits. Below 54° reads cool, above 62° reads warm, and the eight degrees between them are neutral.
Where the boundary sits. Neutral ends at 62°. Above that a complexion reads clearly golden. Our colour tool splits the warm band again at 68° to separate the strongly warm seasons from the mildly warm ones, which is a finer distinction than undertone alone needs.
What goes with it
- Foundation codes
- W, or G for golden. Cool shades will look ashy or grey on you.
- Metals
- Yellow gold, copper and bronze. Silver can look flat or washed out.
- Whites
- Cream, ivory and off-white. Optical white tends to look harsh against warm skin.
- Colours
- Golden-based colours: warm red, coral, olive, mustard, terracotta, warm teal.
- What to watch for
- Foundation that looks grey or chalky in daylight is a shade that is too cool, not too light.
The self-tests, and what each one is actually measuring
People try three tests on themselves, and the tests are not equally good. Knowing what each one measures explains why they sometimes disagree.
Veins at the wrist
Greenish veins are the conventional warm signal. It is the least reliable of the three tests on deep skin, where melanin above the vessel dominates what you see.
Silver against gold
Warm skin tends to look flat beside silver and settled beside yellow gold or copper. As with cool, blunt but aimed at the right axis.
White paper next to the face
In daylight, warm skin reads yellow against optical white and looks settled beside cream. If cream looks better than white, that is a measurement, not a preference.
What is worth knowing about it
Warm undertone is the most over-diagnosed of the three, and the cause is lighting. Almost every environment where somebody assesses your skin — a shop floor, a bathroom, a phone screen — is warmer than daylight, and every one of those pushes a measured hue upward. A great many people who have been told they are warm are measuring the room.
The failure to watch for runs opposite to the cool one. Foundation that looks grey or chalky in daylight is a shade too cool rather than too light, and the instinctive fix — going a shade darker — makes it worse by adding depth to a mismatch of hue. Depth and undertone are separate axes and have to be corrected separately.
Why lighting decides most undertone advice
The band separating cool from warm is eight degrees wide. Ordinary indoor lighting shifts measured skin hue by more than that, so a reading taken under a warm bulb tells you about the bulb. This is the single reason undertone advice contradicts itself so consistently: different people measured the same skin in different rooms.
Our tool white-balances against the whites of your eyes before measuring anything — a reference sitting in the same photo, under the same light, and close to neutral on everyone. It then reports the hue angle in degrees, so you can see how far from the boundary you landed rather than only which side.
Olive is flagged rather than asserted, on a separate axis. A complexion can be warm by hue and still read olive if its chroma sits under 18 — that is a saturation question, not a temperature one, and the two get conflated constantly.
The other two
- Cool undertone
Skin sitting on the pink side of the narrow band every complexion occupies — below 54° of hue in Lab.
- Neutral undertone
Between 54° and 62° of hue — neither pink nor golden dominating. More common than the internet suggests.
Undertone is one axis of three. Combined with depth and clarity it produces the twelve-season system, and combined with depth alone it produces a foundation shade coordinate.
What is measurable here is the hue of your skin in a colour space. Which colours anyone prefers to wear is a matter of taste, and nothing on this page scores or ranks anyone's appearance.