Tory in the navy? (4)
I believe the answer is:
blue
'navy?' is the definition.
(navy is a kind of blue)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for blue that I've seen before include "Such humour < makes conservative" , "Conservative > depressed" , "Miserable; waste (money)" , "Dismal" , "Sea colour" .)