Yellowish-brown polish (4)
I believe the answer is:
buff
This clue is a triple definition!
'yellowish' is the first definition.
(thesaurus)
'brown' is the second definition.
(buff is a kind of brown)
'polish' is the third definition.
(I know that buff is a type of polish)
(Other definitions for buff that I've seen before include "Polish - light colour - expert" , "Dull brownish-yellow - expert" , "with attractively well-developed muscles" , "fan of > nudism?" , "Bare skin - enthusiast" .)