Used on the tails and wings of US Navy aircraft during WW1 from 15 April 1916 to 19 May 1917 when superceeded by first version of star roundel. Info as per official US Navy painting instructions, colors know to be dark blue but exact shade unknown.
Official drawing, republished in Elliot, John M. (1989)       The Official Monogram US Navy &amp; Marine Corps Aircraft Color Guide Vol 1 1911-1939, Boylston, MA:  Monogram Aviation Publications  ISBN:  0-914144-31-6.