Unpleasantly vivid (5)
I believe the answer is:
lurid
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">unpleasantly vivid</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for lurid that I've seen before include "Bright and garish" , "Glaringly bright" , "Gloomily threatening" , "In shocking detail" , "Ghastly in appearance" .)