1 Of, relating to, or having colour. A chromatic colour is a colour having chroma, in contradistinction to an achromatic colour without chroma.
2 Pertaining to musical tones that are sharpened or flattened without changing the key of the passage, or the musical scale containing all twelve semitones of the octave, also called the chromatic scale. Compare diatonic. [From Greek chromatikos of or relating to colour, from chroma, -atos colour + -ikos of, relating to, or resembling]