Muted
Describes a colour that has been softened or dulled, so it is less vivid.
Also: dusty colour, soft colour, greyed colour
A muted colour has had some of its strength taken away, by mixing in grey, white, black or its opposite on the colour wheel. Dusty pink, sage, slate blue and mustard are muted versions of red, green, blue and yellow. Such colours are restful and combine easily, since none shouts. Natural dyes and weathered paint often give muted colours without any effort. The opposite words are vivid, bright and saturated. A scheme that is all muted can feel flat, so a small bright accent is often added.