Brown belt (3)
I believe the answer is:
tan
This clue is a double definition.
'brown' is the first definition.
(tan is a kind of brown)
'belt' is the second definition.
(I've seen this before)
(Other definitions for tan that I've seen before include "belt" , "function" , "Lightish brown colour" , "Bark!" , "Make hide into leather - nicely brown" .)