Warm, cool or neutral? Finding your undertone.

"Am I warm or cool toned?" is the question most colour advice starts with: which neutrals to buy, gold or silver, which foundation, and which half of the seasons you belong to. It's also the question people most often get wrong, because the usual tests are measuring something else. Here's what's going on underneath, and how to test it properly.

What undertone actually is

Skin colour mostly comes from a few pigments. Melanin sets how light or deep skin is, and its brown-black and red-yellow forms add warmth. Haemoglobin in the blood near the surface adds redness, which shifts with oxygenation. Carotenoids from food add yellowness.^3,4,5 Your undertone is the balance of those reds and yellows, once you set aside overall depth.

Colour scientists measure skin in the CIELAB colour space: L* for lightness, a* for redness and b* for yellowness.⁶ "Warm" and "cool" roughly describe the angle between redness and yellowness. Rosier skin leans towards a*, and more golden skin leans towards b*.

Two consequences follow, and both get muddled online:

• Undertone isn't depth. Very fair and very deep skin can both be warm, cool or neutral. As a Clarins UK trainer puts it, people have been "a bit guilty of assuming that warm means darker".⁷ Scales such as Fitzpatrick (which describes how skin reacts to the sun) and Monk (a ten-shade scale) describe something else.^8,9
• Undertone isn't your surface tone today. A tan, redness, rosacea or a cold morning all change surface colour. The traditional advice is to judge undertone on skin that's calm and away from obvious redness, for example along the jaw.⁷

Why it's so hard to see

If you've done three online undertone quizzes and got three answers, you're not alone. There are three reasons.

1. The differences are small, and eyes disagree

In a 2024 study, many people rated the skin of the same photographed faces against colour grids. Individual raters agreed strongly on lightness (intraclass correlations above 0.80) but very weakly on red–yellow undertone (about 0.15–0.16). Averaging lots of raters' answers gave a consistent result (around 0.95), so the signal is there. Any single judgement is just very noisy.¹

2. Light changes the answer

Your brain constantly corrects for the colour of the light it assumes you're under. That's why the internet couldn't agree whether #TheDress was blue-and-black or white-and-gold.¹⁰ Warm indoor bulbs make everyone look more golden, and cloudy daylight or a blue wall can make skin look cooler. Phone cameras make their own corrections on top, and those corrections are measurably less reliable on darker skin.¹¹

3. Surroundings change it too

Colours next to skin change how it looks. In one study, the same faces were judged more or less even-toned depending on the background and hair colour around them.¹² That's a nuisance when you're trying to judge undertone, and it's also the whole reason colour analysis exists.

The home tests, ranked

Ranked from most to least useful. Whichever you try, set up the same way: daylight from a window (not direct sun, not a lamp), no make-up or tinted skincare, hair pulled back, and a white towel or T-shirt over your clothes so their colour doesn't interfere.

1. Paired drapes (best)

Hold a warm and a cool version of the same kind of colour under your chin, one after the other, and compare. You're not looking for the colour you like. You're looking at your skin: which one makes it look clearer and more even, and which brings out shadows, redness or a grey or sallow cast? Those cues come from practitioners rather than lab studies, but because they compare two colours side by side under the same light, they cancel out much of the lighting problem.

• Pure white · cream
• Cool grey · camel
• Fuchsia pink · coral
• Blue-red · orange-red
• Silver · gold
• Blue-teal · green-teal

On-screen swatches are approximate. Use real fabric (scarves, T-shirts, tea towels, cushion covers). Cool is on the left of each pair, warm on the right.

If the warm side wins most pairs, you lean warm. If the cool side wins, you lean cool. If it's a draw, or the pairs disagree, you're probably near neutral, and the more useful question becomes how light, how muted and how contrasting your colouring is. Our guide to seasonal colour analysis explains how those fit together.

2. The white paper test (good, if you know what it does)

Hold a sheet of plain white printer paper next to your bare face in daylight. Next to a known white, a yellow or pink cast in your skin is easier to see.⁷ It works for the same reason photographers use a white or grey card: it gives your eye (or a camera) a reference under the same light. It won't rescue bad light, though. Under a warm bulb the paper and your skin both shift, and your eye partly corrects for both.

3. Gold vs silver (useful, but biased)

This is the same side-by-side idea using metal. The trouble is that most of us already have a favourite, and taste creeps into the judgement. Do it with a friend who doesn't know which you prefer, and treat the result as one vote among several.

4. "Which white do you own?" (a decent tiebreaker)

Look at the whites and neutrals you've kept wearing for years and the ones you gave away. People often hold on to what quietly flatters them: ivory or optic white, camel or charcoal. It isn't scientific, but it's real-world data about you.

5. Sun reaction (tests something else)

"Do you tan or burn?" describes your sun-reactive skin type, the basis of the Fitzpatrick scale, which was developed to guide sun treatment, not colour choices.⁸ It's linked to melanin, but it isn't a measure of undertone, and plenty of people with cool undertones tan.

6. The vein test (least reliable)

The advice says blue or purple veins mean cool and green veins mean warm. But blood is never blue. Veins look blue or green because of physics: skin scatters and absorbs short (blue) and long (red) wavelengths differently, and a vein at the right depth and width darkens the red light reflected from above it more than the blue. A 1996 optics study found the colour you see depends on "the scattering and absorption characteristics of skin… the oxygenation state of blood… the diameter and the depth of the vessels, and… the visual perception process".² Your undertone isn't on that list. Vein colour also changes with lighting and with the skin around it, which is the very thing you're trying to judge. At best it's a weak hint, so don't let it overrule a drape test.

Neutral, olive and deeper skin

Neutral simply means neither side clearly wins. In an on-screen study that paired 15 skin-tone samples with 128 colours, observers rated neutral-undertone samples as harmonious with colours from every season,¹³ so if you're neutral you often have the widest choice. What decides your best colours is how light, how muted and how contrasting you are.

Olive is the beauty industry's term for skin with a subtle green, grey-green or yellow-green cast, which can occur at any depth and can be hard to place as warm or cool.¹⁴ It isn't a well-defined category in skin-measurement research, so take any single "olive palette" with a pinch of salt. Paired drapes work just as well here.

On deeper skin, Clarins UK's trainer suggests looking for golden or honey tones as a sign of warmth and red or terracotta tones as a sign of coolness, rather than for yellow or pink.⁷ Lighting matters even more. Cameras make more exposure and white-balance errors on darker skin,¹¹ so trust a daylight mirror over a selfie, and be wary of any app that gives you one confident label from one photo.

What to do with your answer

• Neutrals first: warm-leaning people often look fresher in cream, camel, warm navy and chocolate. Cool-leaning people often do better in crisp white, grey, true navy and charcoal.
• Metals and frames: gold and bronze vs silver and pewter, or, if you're neutral, rose gold or mixed metals.
• Base make-up: undertone is what foundation ranges mean by "warm", "neutral" and "cool". Swatch on your jaw in daylight.
• Your season: undertone splits the seasons in half (Spring and Autumn lean warm, Summer and Winter lean cool), but it's only one of four traits. Lightness, chroma and contrast decide the rest.

Warmth is the hardest of those four traits to read reliably, so whatever method you use, it's fine for the answer to be "leans warm" rather than a hard label.

How DayDrape handles undertone

We're building DayDrape to treat undertone as a measurement with error bars, not a verdict. The app is designed to check your light before each photo, use a plain sheet of white paper as a reference if you have one (it's optional), and read warmth as a hue angle across your skin, hair and eyes. Because people and cameras disagree on undertone, it will show a range rather than a flat "warm" or "cool". It's still in development.

Sources

This article is general styling information, not dermatological advice. If you have a skin condition that changes your skin colour, a dermatologist is the right person to ask. We link every source we rely on; if you spot an error, tell us and we'll correct it.