After a very difficult task of deciphering some very clever clues I've gone for a clue that ticks the boxes of being a superb example of a cryptic definition with the 'Penny Drop' factor if seen cold in a cryptic crossword . There are a couple more succinct cryptic defs but this one just seems to fit the bill.
Battleship grey?
Well done Bernie at POST 3
Your prize is:
(I'm working from a tablet and struggling to copy & paste. So if this doesn't hyperlink can someone do it for me)
https://m.youtube.com/#/watch?v=2fXJqm7XoCc