Windshield coloring (4)
I believe the answer is:
tint
'windshield coloring' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for tint that I've seen before include "Hue, shade" , "A slighth shade of colour" , "Quality of colour" , "Shade; colour slightly" , "work for coiffeuse?" .)