Cool
undertone

How to recognise it

In daylight, on bare skin, with your hair tied back. Indoor bulbs push every skin towards warm, which is why cool undertones are so often misread indoors and correctly read by a window.

• — Silver held against your jaw lifts the face. Gold beside it looks heavy, or makes the skin look slightly sallow.
• — Against a sheet of plain white paper, the skin reads pink, rosy or faintly blue rather than yellow.
• — The veins at your wrist look blue or purple, though this is the weakest of the tests.
• — Foundations that have turned orange or muddy on you were almost certainly warm shades on cool skin.
• — A pure optic white shirt suits you better than cream or ivory.

Measure it rather than guess

The home tests all depend on the light you happen to be standing in and on your memory of the first metal while you hold up the second. The undertone finder reads the colour of two patches of your cheek from a photograph and places it on the yellow-to-blue axis directly. It runs in your browser, it is free, and nothing is uploaded.

Foundation

Look for cool, rose, porcelain, beige-rosé or a shade code ending in C. Avoid golden, honey, caramel and sand, which are the labels most ranges lead with and the ones that go orange on cool skin. Where a range offers the same depth in two temperatures, take the cooler of the two, and take it knowingly: most formulas oxidise slightly warmer over the first twenty minutes, so a shade that matches exactly in the first thirty seconds will be a little too warm by the time you leave the house.

Test along the jaw and onto the neck, in daylight, and look again twenty minutes later. There is one trap specific to cool skin: if you also have visible redness across the cheeks or the nose, a pink-leaning foundation stacks pink on pink and the face reads flushed all over. The better route is a neutral-cool shade over a green-tinted corrector used only where the redness actually is, rather than a cooler foundation everywhere. Under the eye, a concealer with a peach or salmon base cancels the blue that cool skin shows there — this is the one place where warmth helps.

Blush, bronzer and lips

Cool pink, raspberry, mauve, plum and berry all look as though the colour rose to the surface rather than being placed on it. Bronzer is the difficult one: most are built warm, and a taupe or cool-brown bronzer reads as a shadow on cool skin where an orange one reads as a stripe. For lips, blue-based reds and cherry sit naturally, and cool nudes with pink or mauve in them rather than caramel.

Coral, peach and warm terracotta are the ones that fight, and on cool skin they can read slightly muddy. Again, that is information rather than a prohibition. A coral blush layered over a pink one, or a warm lip against a cool blush, is a contrast you can choose deliberately.

Metals

Silver, white gold, platinum and gunmetal. Pewter and steel behave the same way. Yellow gold does least for cool skin, though rose gold — which has pink in it — is the easy exception and often reads as neither. For eyes, taupe, grey, cool brown, plum and slate-blue shadows work with the undertone instead of against it.

What is a myth

That cool means pale. It is the most persistent error in this whole subject and it has real consequences: deep skin is very often cool, with a blue or red cast under it, and the assumption that the deepest shades in a range should all be golden is why so many ranges have nothing that matches. Cool runs the entire length of the depth scale.

Two more. Cool skin is not barred from gold, it simply gets less help from it. And a pink blush is not the safe default for cool skin the way it is usually described: the depth and the clarity of the pink matter at least as much as its temperature, and a bright clear pink on low-contrast colouring will overpower the face regardless of how correctly cool it is.