Undertone is the single most important measurement in colour analysis. Everything else — your season, your palette, what metals to wear, which neutrals work — flows from it. And yet most guides bury the answer in vague language about "warmth" that doesn't actually tell you what to look for.
Here are seven tests. Do all of them. A clear pattern will emerge.
Test 1: The vein test
Look at the inside of your wrist in natural daylight — not under warm lamplight, not near a window with afternoon orange sun. Flat, neutral daylight.
- Greenish or olive veins → warm undertone. The yellow pigment in your skin is shifting the blue of the vein toward green.
- Blue or purple veins → cool undertone. The vein reads true blue because there's no warm pigment diluting it.
- Hard to tell — seems like both → likely neutral. This is a real result, not a cop-out.
Test 2: The white fabric test
Hold a piece of stark white fabric near your bare face. No jewellery, no makeup. What does your face do next to pure white?
- Face looks yellowish or slightly sallow → warm undertone. Pure white is too cool and blue for you, making your yellow pigment visible by contrast.
- Face looks slightly pink, ruddy, or washed out → cool undertone. The stark white is competing with your natural pink-blue tones.
- No particular cast — face looks fine → neutral undertone.
Test 3: The cream/off-white test
Repeat the fabric test with cream or off-white. The result should reverse: warm undertones look better against cream than white, cool undertones look worse. If the reversal is dramatic, your undertone is strong. If it's subtle, you're toward neutral.
Test 4: The jewellery test
Hold gold and silver against your bare skin, one at a time, in natural light.
- Gold looks harmonious, silver looks stark → warm undertone.
- Silver looks clean and refined, gold looks muddy or orange → cool undertone.
- Both look equally fine → neutral. You are the rare person who can wear both metals.
Test 5: The sun reaction
Think about what happens to your skin in the first week of sun exposure.
- Tans easily, goes golden → warm undertone. Higher melanin, yellow-based.
- Burns, then peels, then maybe tans — or just burns → cool undertone. Pink-based skin with lower initial melanin response.
- Burns a little, then tans to a medium tone → neutral.
Note: this test matters less for very deep skin tones, where sun reaction is less visually distinguishing.
Test 6: Your natural hair colour
Use your uncoloured hair as it was in your twenties (or current, if undyed).
- Golden blonde, strawberry blonde, auburn, copper, warm brown → warm. These pigments contain phaeomelanin — the yellow-red molecule.
- Ash blonde, cool medium brown, black (with blue-black sheen), silver or white with no yellow → cool.
- Plain medium brown — not golden, not ashy → neutral.
Test 7: The eye test
Look closely at your irises in daylight. The dominant hue matters, but so do secondary tones.
- Brown, hazel, warm green, amber, olive-green → warm. Look for the golden and brown flecks.
- Blue, grey, cool green (no brown), black → cool.
- Mixed — brown with green, grey-green, hazel with blue → likely neutral or close to the border.
Reading the pattern
If 5–7 of your results point in the same direction, your undertone is clear. If you split 4–3, you're likely neutral or on the border between two seasons (for example, between Soft Summer and Soft Autumn). Both are valid results — the app's analysis is specifically designed to catch those borderline cases, which a 7-question quiz cannot do reliably.
Once you know your undertone, the next question is value (how light or dark your colouring reads overall) and chroma (how muted or vivid). Those three measurements together place you in one of twelve sub-seasons.