01
Undertone is not skin depth
Depth describes how light or deep the skin appears. Undertone describes its underlying colour behaviour. Fair skin can be warm, cool, neutral or olive, and so can deep skin. Separating these two ideas prevents rules such as dark skin always being warm or pale skin always being cool.
Surface tone can change from sun, redness, acne, medication or lighting. Undertone is more stable, though it can be difficult to see directly. That is why comparison tests work better than staring at the skin alone.
Warm
Often golden, peachy or yellow leaning. Warm colours tend to look integrated rather than separate.
Cool
Often rosy, bluish or red leaning. Cool colour families tend to make the skin look calmer or clearer.
Neutral
Warm and cool comparisons are similarly successful, especially in softened rather than extreme shades.
Olive
A green-gold or muted cast that may reject foundations that are too pink, orange or saturated.








