Colour used in painting enamels (5)
I believe the answer is:
tinge
'colour' is the definition.
(I know that colour can be written as tinge)
'in painting enamels' is the wordplay.
'in' indicates a hidden word.
'TINGE' is hidden within 'painting enamels'.
'used' acts as a link.
(Other definitions for tinge that I've seen before include "Small quantity of (differing) colour" , "Slight but perceptible amount" , "Colour slightly; trace" , "A slight shade of colour" , "Smattering" .)