Colour art theory: Tones are colours with gray. Less or more greyed. Soft, muted, subdued...are therms used to describe tones. They could be very lightly softened with light appearance to higher saturated tones of pigments - muted darker colours. Not so dark as shades, but with relatively darker appearance. I called them " slightly dark colours". Tones have less pigments than shades! Low chroma.