Animal intended to lose a colour (7)
I believe the answer is:
pigment
'colour' is the definition.
(I've seen this before)
'animal intended to lose a' is the wordplay.
'animal' becomes 'pig' (pigs are animals).
'intended' becomes 'meant' (to mean something is to intend it).
'to lose' suggests deleting specific letters.
'meant' with 'a' removed is 'ment'.
'pig'+'ment'='PIGMENT'
(Other definitions for pigment that I've seen before include "Paint" , "Colourful substance" , "Substance giving colour" , "become imbued" , "Colouring substance" .)