undertone

An underlying or implied tendency or meaning; an undercurrent.

A tone of low pitch or volume, especially of spoken sound.

A pale or subdued color.

A color applied under or seen through another color.

A low or subdued tone; a tone less forcible than is usual, as in speaking: as, to say something in an undertone.

A state or degree of tone, as of the physical or mental faculties, below their usual condition. The color of a pigment when seen in very thin layers on a white or light-colored surface.

In musical acoustics: Same as combinational tone (which see, under tone), One of a series of tones reckoned downward from a given tone in exactly the same way that the series of overtones or harmonics is reckoned upward. The interval from the given tone to the first undertone is an octave; to the second, an octave and a fifth;

A low or subdued tone or utterance; a tone less loud than usual.

an auditory tone of low pitch or volume