Often described as looking comfortable in both warm and cool colours, without one direction reading as a clearly better match.
Why informal tests aren’t reliable
An inconclusive result from an already-unreliable informal test isn't meaningful evidence of a 'neutral' category — it more often just reflects the test's own limitations.
Camera white balance and screen calibration both shift how skin looks in a photo — a phone photo taken under warm indoor light can look distinctly warmer than the same skin looks in daylight, and vice versa.
Try a genuinely wide range of colours and metals — a neutral undertone is one real reason both warm and cool choices can look equally comfortable.
A wide range of colours commonly work, since neither direction dominates.
No particular direction is flagged — comparison remains the most useful approach.
A 'neutral' reading means that, under the light and context at hand, the returned light shows no clear lean — the golden contribution from melanin's absorption of short wavelengths and the pink contribution from blood roughly offset each other. Colour vision is relative: the visual system adapts to the prevailing light and judges hues against what surrounds them, so a small lean that exists physically may simply not be salient. That is why 'neutral' is often the result when people compare warm and cool samples and find both comfortable. It is a statement about a comparison, not about the skin's composition.
Why the quick tests mislead: An inconclusive vein or jewellery test is sometimes taken as proof of a neutral undertone, but an unreliable test failing to give an answer carries no information of its own.
Sources: The optics of human skin (Anderson & Parrish, Journal of Investigative Dermatology 77, 13–19, 1981); Skin Optics Summary (Steven L. Jacques, Oregon Medical Laser Center News, January 1998); Human skin color; Simultaneous Color Contrast Increments with Complexity and Identity of the Target Stimulus (Grasso et al., Life 15:257, 2025)