This military don sounded out transport solution (5)

I believe the answer is:

khaki

'this military don' is the definition.
(the military might don khaki uniforms)

I don't understand the remainder of the clue.

(Other definitions for khaki that I've seen before include "Military camouflage colour" , "Army uniform cloth" , "Army dress material" , "Dull yellowish-brown" , "Dark green colour" .)

I've seen this clue in The Times.

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