These are the weights the tool applies to each at-home check, not measured optical values. No single check is reliable on its own, which is exactly why the tool runs all four and weighs them against each other rather than asking one question and announcing an answer.
A cool undertone has a pink, red or blue base beneath the surface. As with warm, it is independent of depth. Cool undertones occur in very fair skin and in very deep skin, and the assumption that fair equals cool is as unreliable as the assumption that deep equals warm.
Cool is the undertone most often misdiagnosed, and usually in one direction. Foundation ranges have historically been built warm, so many people spend years in a shade slightly too golden for them, conclude they must be warm because that is what they wear, and never test it.
The four checks, in order of how much they count
Veins, weighted at 2 and the single most consistent check. In daylight, at a window, look at the inside of your wrist. Blue or purple veins point cool. Do not do this under a lamp.
Jewellery, weighted at 1.5. Silver, white gold and platinum tend to look clean against cool skin, while gold can look slightly yellow or brassy next to it. Watch the skin rather than the metal, and allow for the fact that whichever metal you usually wear will look normal.
Sun response, weighted at 1. Cool skin more often burns before it tans, and burns pink rather than bronze. This check is the least dependable of the four because sunscreen habits affect it heavily.
White fabric, weighted at 1. Cool skin usually looks clean and bright against pure optical white, and can look slightly yellow or tired against cream.
If some checks say cool and others say warm, that is neutral. Neutral is a real category, not a failure to decide, and it is more common than either extreme.
Olive can read cool on the white-fabric check because of its green cast. If cool-toned pink foundations look grey on you rather than clean, look at olive.
The principle behind every suggestion below
Colours with a blue base sit with the skin, and colours with a yellow or golden base sit against it. The direction is the opposite of warm and the logic is identical.
Colour and makeup
Undertone sets direction, not intensity. It says move towards the blue side of a colour. How light, deep or bright that colour should be is a separate decision the colour season tool handles.
Worth reaching for
Foundation labelled cool, rosy or with a C in the shade code
Silver, white gold, platinum and steel
Pure optical white rather than cream at the neckline
Blue-based reds, berry, emerald, navy, true grey and cool pink
Works against it
Foundation with a golden or yellow base, which tends to look orange or mask-like
Cream and ivory directly against the face, which can look sallow
Orange, mustard, camel and warm brown at the neckline
Assuming cool means no warm colours: a blue-leaning red or a cool coral works fine
The lipstick shortcut
If a blue-based red makes your teeth look whiter and an orange-based red makes them look yellow, you are cool.
This is one of the quicker confirmations available, because the contrast against tooth enamel is easier to judge than the contrast against skin. It is not definitive on its own, but it agrees with the vein check often enough to be worth trying.
Where people go wrong
Assuming pale skin is automatically cool
Depth and undertone are separate axes. Very fair skin is frequently warm, and very deep skin is frequently cool. Run the checks rather than assuming from complexion.
Staying in a warm foundation out of habit
Shade ranges have historically skewed golden, so many cool-undertoned people have only ever worn something slightly too warm and have normalised it. If your foundation looks fine in the mirror but orange in photographs, that is the usual sign.
Reading redness as a warm undertone
Rosacea, flushing and general redness are surface conditions, and red on the surface usually indicates a cool base rather than a warm one. Surface redness is a reason to check carefully, not evidence of warmth.
Common questions
Yes, and it is common. Undertone and depth are independent. Deep skin with a cool undertone often suits blue-based reds, berry tones and silver jewellery, and is poorly served by the golden-heavy foundation ranges that dominate the deeper end of the market.
Bathroom and shop lighting is usually warm, which hides a too-warm foundation. Camera flash is closer to neutral and exposes it. If the mirror and the photograph disagree, trust the photograph.
No, though they are related. Undertone is one of four things a colour season depends on, alongside depth, contrast and clarity. A cool undertone narrows you to the cool seasons but does not tell you which of them, which is what the colour season tool works out.
The safety note explaining that the sun-response clue does not call for UV exposure.
Last checked 2026-07-31
Not sure this is you?
The tool runs all four checks, weighs them against each other, and tells you which ones disagreed. When the evidence is mixed that is the useful information, because mixed evidence is what neutral actually means.
