Subtle color (4)
I believe the answer is:
tint
'subtle color' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for tint that I've seen before include "work for coiffeuse?" , "Shade; colour slightly" , "A slighth shade of colour" , "(Softer variety of) colour" , "A slight shade of colour" .)