Reviewed by the Tonebook color team · Updated June 2026
Your undertone is the subtle hue beneath your skin's surface, and it doesn't change with a tan. There are four: warm (golden/peach), cool (pink/blue/red), neutral (a balance), and olive (a green-grey cast that can sit over any depth). The fastest at-home checks: look at your wrist veins (green = warm, blue/purple = cool), and notice whether gold or silver jewelry flatters you more (gold = warm, silver = cool). Undertone is the first input of a full color-season analysis.
| Undertone | Looks like | Best metals | Tends toward |
|---|---|---|---|
| Warm | Golden, peach, yellow cast | Gold, bronze | Spring / Autumn |
| Cool | Pink, red, bluish cast | Silver, platinum | Summer / Winter |
| Neutral | Balanced, hard to place | Both work | any soft/true season |
| Olive | Subtle green-grey overlay | Muted gold | Soft Autumn / Summer, Deep |
Why the tests disagree. Undertone is one of three axes — undertone, value (how light/deep you are) and chroma (how bright/muted) — so two people with the same undertone can still be different seasons. At-home tests read undertone only; a full analysis reads all three together.
Rather than asking you to judge your own veins, Tonebook samples real pixels from a single selfie, corrects for the room's lighting to read your true undertone, and reports warm, cool, neutral or olive with a confidence label — then places you in one of 12 seasons. It's built to read every undertone across Fitzpatrick I–VI, so deep skin is read as accurately as fair skin.
Tonebook reads one selfie, places you in the 12-season system, and builds outfits in your colors — inclusive across Fitzpatrick I–VI. First analysis free.
Get Tonebook for iPhoneThat's exactly what 'neutral' means — a balance of warm and cool with neither dominating. Many people are neutral-leaning-warm or neutral-leaning-cool, which is why a single at-home test often feels inconclusive.
No. Your surface color (and Fitzpatrick type) can deepen with sun, but your underlying undertone stays the same. That's why color analysis is based on undertone, not tan.
Olive is a green-grey cast that can sit over fair, medium or deep skin. It's often misread as 'sallow' under bad lighting. Olive skin usually suits muted, slightly warm-neutral palettes and muted gold over bright silver.
It's a useful first signal but not definitive — skin thickness and lighting skew it. Pair it with the jewelry and white-paper tests, or run a selfie analysis that measures undertone directly.