TONE (3)

Tone, n. 1. 1. (Physiol.) Quality, with respect to attendant feeling; the more or less variable complex of emotion accompanying and characterizing a sensation or a conceptual state; as, feeling tone; color tone.
2. 2. Color quality proper; — called also hue. Also, a gradation of color, either a hue, or a tint or shade.
She was dressed in a soft cloth of a gray tone. Sir G. Parker. 3. 3. (Plant Physiol.) The condition of normal balance of a healthy plant in its relations to light, heat, and moisture.