Warm White
There is no such thing as a neutral white. Every white paint is tinted, and the tint decides how the colour behaves in a particular light. Warm whites are those tinted toward yellow, red or brown; cool whites are tinted toward blue, green or violet. The tint is usually far too small to see in the tin and quite large enough to see on four walls.
The practical test is not the colour chip but the light the room receives. A room with northern light or a large amount of green outside the window receives cool, slightly green light, and a cool white in that room will read as grey. The same white in a room with strong afternoon sun can look perfectly clean. This is why a white that worked in one house so often fails in the next.
Warm whites make a room look older and more furnished than cool whites do, because they suggest a surface that has aged rather than one that has just been painted. They also flatter almost every timber and every natural fibre, and they make gilding, brass and copper look intentional rather than orange.
Where a scheme uses several whites, keep them all on the same side of neutral. A warm white wall with a cool white ceiling reads as a mistake even to people who cannot say what is wrong.