Colour of ape is odd (5)
I believe the answer is:
sepia
'colour' is the definition.
(I know that sepia is a type of brown)
'ape is odd' is the wordplay.
'odd' indicates anagramming the letters.
'ape'+'is'='apeis'
'apeis' is an anagram of 'SEPIA'.
'of' is the link.
(Other definitions for sepia that I've seen before include "Rich reddish-brown colour" , "A greyish brown" , "Sort of ink" , "source of ink" , "Former photographic pigment" .)