Pigment more likely to leak, might you say? (5)

I believe the answer is:

sepia

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'pigment' is the definition.
(sepia is a kind of pigment)

I don't understand how the rest of the clue works.

(Other definitions for sepia that I've seen before include "Reddish-brown colour as in old photos" , "Colour of old photographs" , "cuttle" , "Colour from cuttlefish ink" , "Reddish-brown colour - easy as pie" .)

I've seen this clue in The Times.

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