You can wear the perfect depth of foundation and still look grey, ashy, or muddy. When that happens, the shade number isn't the problem — your undertone is. And on deep, melanin-rich skin, undertone is the single most overlooked reason makeup looks "off."

In this guide you'll learn what undertone really is, the four undertones that show up on dark skin (including the one most brands ignore), and three simple at-home tests to find yours — so every foundation, lipstick, and colour you buy actually flatters you.

Undertone vs depth: they're not the same thing

Two people can share the exact same depth — how light or dark their skin is — and need completely different foundations, because their undertone is different. Depth is the surface. Undertone is the colour humming underneath it.

Depth gets your foundation close. Undertone is what makes it disappear. If you've never matched undertone before, start here, then use our full foundation shade-match guide for deep skin to put it into practice.

The four undertones on melanin-rich skin

• Warm — golden, yellow, or honeyed warmth. Warm-toned deep skin glows in golds, ambers, and warm browns.
• Cool — a blue, red, or deep espresso base. Cool-toned deep skin loves rich berries, blue-reds, and true jewel tones.
• Neutral — a balance of warm and cool, with no strong pull either way. The most flexible undertone.
• Olive — a green or grey cast layered over any depth. Olive is extremely common on deep skin and almost always ignored — which is exactly why so many foundations turn olive skin grey or ashy.

If foundations constantly leave you looking dull or grey no matter the depth, there's a strong chance you're olive and have been sold shades that fight your undertone.

Three at-home tests to find your undertone

1. The daylight jewellery test

In natural light, hold gold jewellery to your face, then silver.

• Gold looks more flattering → likely warm.
• Silver looks more flattering → likely cool.
• Both look great → likely neutral.

2. The white-fabric test

Hold a pure-white cloth or paper next to your bare, clean face in daylight. Against true white, your skin's real undertone shows:

• A yellow or golden cast → warm.
• A red, blue, or pink cast → cool.
• A green or grey cast → olive.

3. The "what greys you out" test

Think about the shades that make you look tired or ashy versus lit-up. Colours that flatter you usually share your undertone; colours that dull you usually fight it. Your past makeup wins and fails are real data — use them.

Still not certain? Our Find Your Shade quiz reads your undertone and depth together and points you to the right match — no guesswork.

Why undertone decides more than your foundation

Once you know your undertone, it guides every colour choice:

• Foundation & concealer — the right undertone melts in; the wrong one greys or oxidizes. (See why foundation oxidizes on deep skin.)
• Lipstick — warm skin glows in warm nudes and brick reds; cool skin sings in berries and blue-reds. Explore shades in My TLips.
• Eyeshadow & colour — undertone tells you which shades will pop and which will disappear. Browse My TEyes.

Put your undertone to work

Our My TFace range is built with deep-skin undertones in mind — including olive tones most brands skip — so your base honours the colour underneath your skin instead of fighting it. True to tone, no ashiness, zero flashback.

Know your undertone? Take the Find Your Shade quiz to lock in your match, then find it in My TFace.

Your Beauty Is Inside.