Colour of jet (5)
I believe the answer is:
black
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">colour of jet</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for black that I've seen before include "Colour of coal" , "Very darkest colour" , "Chess player" , "Without light" , "Sort of guard, panther, jack or pudding..." .)