The colour of a topless figure (5)
I believe the answer is:
umber
'the colour' is the definition.
(umber is a kind of colour)
'a topless figure' is the wordplay.
'a topless' means to remove the first letter.
'figure' becomes 'number' (I've seen this before).
'number' with its initial letter taken off is 'UMBER'.
'of' is the link.
(Other definitions for umber that I've seen before include "Natural pigment" , "Brownish pigment" , "Natural colouring matter, dark brown" , "Earthy colour" , "Dark brown (pigment)" .)