Add color to (4)
I believe the answer is:
tint
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">add color to</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 tint that I've seen before include "work for coiffeuse?" , "Hue, shade" , "A slight shade of colour" , "(Softer variety of) colour" , "Hair dye" .)