Antique photo tone (5)
I believe the answer is:
sepia
'antique photo tone' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for sepia that I've seen before include "Brown of old photos" , "Old drawing" , "Brown pigment produced from cuttlefish ink" , "Pigment got from cuttlefish ink" , "Sort of ink" .)