Overtone
The surface color cast that can shift with tanning or light, unlike the fixed undertone beneath it.
Overtone is the color that sits on the surface of the skin, or of a fabric or drape, the layer you see first, as opposed to undertone, which is the fixed warm-or-cool quality underneath it. Overtone can change with a suntan, a flush of color after exercise, redness, sun damage, or even the color of the light in the room, while undertone stays the same year-round. The distinction matters because people often misjudge their own undertone from a tanned or sunburned overtone, testing warm in August and cool in February, or reading a photo taken under warm indoor bulbs as evidence of a warmth that isn't really there. Seasonal color analysis is built on undertone, not overtone, which is why professional draping insists on bare, makeup-free skin, natural daylight, and no recent tanning, so the surface noise cannot be mistaken for the underlying signal.
Why it matters
Confusing overtone with undertone is one of the most common self-analysis mistakes, and it is why the same person can seem to test differently depending on the season, the light, or how recently they tanned. Knowing the difference keeps a color reading stable rather than shifting with the weather.