Subtly colour or dye (4)
I believe the answer is:
tint
(Other definitions for tint that I've seen before include "A slight shade of colour" , "(Softer variety of) colour" , "Hair dye" , "Shade; colour slightly" , "'Shade, tone (4)'" .)
I believe the answer is:
tint
(Other definitions for tint that I've seen before include "A slight shade of colour" , "(Softer variety of) colour" , "Hair dye" , "Shade; colour slightly" , "'Shade, tone (4)'" .)