Dull brown (4)
I believe the answer is:
drab
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">dull brown</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for drab that I've seen before include "Dull and colourless" , "Dreary and colourless" , "Dull - dreary" , "Dull, uninteresting" , "Dowdy" .)