Cool, warm or neutral: find your undertone.
Six observations, from the veins on your inner wrist to the white that flatters you, place your skin as cool, warm, neutral or olive. You get the tone, six colours that sit well with it, and the letters to look for on a foundation label.
Cool, warm, neutral or olive: six looks at your skin settle it.
Undertone is the hue beneath the surface. It is not the same as depth, it stays where it is while a tan comes and goes, and no single test decides it, so this tool asks six and reads the agreement between them.
Daylight, bare skin, no coloured wall or screen light close by: an indoor bulb turns the same wrist warmer, and a bright top throws its own colour on to your face.
Coolundertone
Six colours for this tone
On a foundation label
- Ccool
- Nneutral
- Wwarm
- Rrosy
- Ggolden
- Oolive
The letters differ from one label to the next, and the number beside them is depth, not undertone: 2N is lighter than 6N. Hold 3 shades side by side on the jawline in daylight, then look again after 10 minutes.
Undertone is not depth
Depth runs from fair to deep and moves with the season. The hue underneath stays put, so a tan gives you a deeper version of the same undertone rather than a warmer one, and every depth exists in all four tones. Most faces move 1 to 2 shades of depth between winter and late summer, which is a reason to keep two numbers in the same letter.
How it works.
- Stand by a window in daylight, with bare skin on the face and wrist and nothing strongly coloured close by.
- Answer six observations, one per screen: veins, metals, whites, sun, colours and your natural flush. Back changes an answer.
- Read your undertone, the six colours that sit well with it and the letters to look for on a foundation label, then save the card.
Depth and undertone are two different readings
Colour matching in cosmetics works on two axes. Depth is how light or deep the skin is, set by how much melanin it holds, and it moves: 2 weeks of strong sun take most people a shade deeper, and the colour fades again over 4 to 8 weeks. Undertone is the hue underneath, the mix of haemoglobin in the small vessels, carotenoids from food, and which type of melanin the skin makes. That mix holds steady, so a tan gives you a deeper version of the same undertone rather than a warmer one. Most foundation labels carry both readings at once: the number is depth, the letter is undertone, which is why 2N is lighter than 6N while both are neutral. The undertone guide goes through the letter systems shade by shade.
Why the six tests are heuristics
None of them measures anything. The vein test reads blood vessels through a scattering surface, so a vein can look green only because the skin above it scatters more yellow, and it looks blue on very light skin whatever the hue underneath. The metal test and the white-fabric test are contrast tests: you judge which of two colours makes the face look fresher, and both fall apart under an indoor bulb or beside a coloured wall. The sun question is the weakest of the six, because how easily skin burns follows depth more closely than hue. Agreement carries the result, which is why the tool names a tone only when at least 4 of 6 observations point the same way and returns neutral when none does. The seasonal colour systems rest on the same observations and have no clinical validation either: they are style tools, not measurements.
Testing a shade on the jawline
Put 3 shades side by side along the jawline, on bare skin, in daylight, and look again after 10 minutes, because some formulations oxidise and settle half a step deeper or more orange. The shade that disappears is yours; the one that turns grey is fighting your undertone, which is what happens when olive skin is sold a pink-based shade. Note the date on a bottle when you open it, since most liquid foundations carry a 6 to 12 month period after opening, printed as the open-jar symbol that the expiry guide explains. If a new base itches or stings, look at the ingredient list before the shade: the 26 declarable fragrance allergens have to be named on the carton.
Frequently asked.
Does a tan change my undertone?
No. A tan changes depth, the amount of melanin near the surface, while the hue underneath stays where it was. In practice you keep the same letter on a foundation label and move up a number or two for the summer.
My veins look blue on one wrist and green on the other. What does that mean?
Usually that the skin above them differs in thickness, not that your undertone is split. Take the third option and let the other five observations decide, which is what the 4 of 6 rule is there for.
What is an olive undertone?
A neutral with a green-grey cast, and it appears at every depth from fair to deep. Pink-based shades often turn grey on it within an hour, while a base coded O, or a yellow-green one, stays flat and even.
Can skin be deep and cool, or fair and warm?
Yes. Depth and undertone are independent readings: fair skin can be warm, deep skin can be cool, and either can be neutral or olive. A shade only matches when both readings are right.
How reliable is a six-question self-check?
It is a set of heuristics, not a measurement. Done in daylight on bare skin the six observations usually agree, and the tool names a tone only when 4 of 6 point the same way. If you get neutral, test a neutral shade with one warm and one cool shade beside it.
Does the tool keep my answers?
No. Everything runs in your browser, nothing is sent anywhere and nothing is stored, so a reload starts the six questions from the beginning. The result card is drawn on the page and exists only if you download it.
Guides behind this tool
Beauty
Skin undertone: how to find yours and match a foundation
Beauty
When make-up expires: the open jar symbol and 30 months
Beauty
Fragrance allergens in cosmetics: what must be on the labelMore tools
The Undertone Finder is a colour aid built on six observations you make yourself, not a measurement of your skin. It says nothing about skin health, and it does not replace holding three shades against your own jawline in daylight before you buy. This page is for general information and does not replace advice from a dermatologist, physician or qualified practitioner.