Azure or ultramarine, eg (4)
I believe the answer is:
blue
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">azure</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >'<span class="explanation-format__original">ultramarine eg</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(ultramarine is a kind of blue)</span><br/ ><br/ ></span>
(Other definitions for blue that I've seen before include "Sky-coloured" , "e.g. Indigo" , "Miserable - cerulean" , "Indecent" , "Varsity sportsman" .)