Blue shade (4)
(Other definitions for navy that I've seen before include "Ships-of-war" , "Shade of the marine forces" , "Colour; fighting force" , "military arm" , "Armed force" .)
'blue shade' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for teal that I've seen before include "Small freshwater duck and colour" , "Strange tale of a duck" , "Small river duck" , "Variety of small ducks" , "Dark green-blue; duck" .)