Dyed (7)
I believe the answer is:
stained
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">dyed</span>' is the definition.<br/ ><span class="explanation-format__explanation">(staining is a kind of dyeing)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for stained that I've seen before include "Like many church windows" , "Marked, discoloured" , "Soiled" , "Church feature - side sold was wanting (anag)" , "___ glass" .)