Colour that's fashionable, time after time (4)
I believe the answer is:
tint
'colour' is the definition.
(I know that tint is a kind of colour)
'fashionable time after time' is the wordplay.
'fashionable' becomes 'in' (in can mean fashionable or trendy).
'time' becomes 't' (abbreviation).
'after' is a charade indicator (letters next to each other).
'time' becomes 't' (abbreviation).
'in'+'t'='int'
'int' put after 't' is 'TINT'.
'that's' acts as a link.
(Other definitions for tint that I've seen before include "Hue, shade" , "work for coiffeuse?" , "Quality of colour" , "Shade; colour slightly" , "(Softer variety of) colour" .)