What does "chromatic" mean?

Chromatic: (Mus.) Proceeding by the smaller intervals (half steps or semitones) of the scale, instead of the regular intervals of the diatonic scale. Note: The intermediate tones were formerly written and printed in colors. Chromatic aberration. (Opt.) See Aberration, 4. -- Chromatic printing, printing from type or blocks covered with inks of various colors. -- Chromatic scale (Mus.), the scale consisting of thirteen tones, including the eight scale tones and the five intermediate tones.