Neutral undertone
An undertone that leans neither clearly warm nor clearly cool, the most common and hardest to read result.
A neutral undertone sits in the middle of the warm-to-cool hue axis, without a strong enough lean toward yellow or blue to read clearly as one or the other. It is, by most accounts, the most common real-world outcome and also the hardest one to diagnose, because it does not produce the obvious, confident signal that a strongly warm or strongly cool undertone does. People with a neutral undertone can often wear both gold and silver jewelry, and both warm and cool versions of a color, reasonably well, which is convenient in practice but frustrating when trying to pin down a single season. Self-testing tends to over-report neutral undertones too, partly because ambiguous evidence gets rounded to neutral by default, and partly because confirmation bias pushes people toward whichever answer they expected before they started testing. A trained eye comparing several indicators side by side, rather than any single home test, gives the most reliable read on a genuinely neutral case.
Why it matters
If your undertone reads neutral, most single home tests, the vein test, the jewelry test, will not give you a clear answer on their own, and side-by-side comparison across several different methods becomes more important than it usually is.