Roundel used by the United States armed forces from 19 August 1919 to 6 May 1942 until red dot removed to avoid confusion with Japanese insignia. Superseded very similar roundel whose colors and proportions differed slightly - the original version having the colors from the US flag, and a center dot 1/3 of the outer radius. This version has a center dot constrained by the inner vertices of the star, a size that does not translate into an even fraction.
Grumman F3F-2 USN F3F-2

colors consistent as per this &amp; this
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. 
 Elliot, John M. (1989)       The Official Monogram US Navy &amp; Marine Corps Aircraft Color Guide Vol 2 1940-1949, Sturbridge, MA:  Monogram Aviation Publications  ISBN:  0-914144-32-4. 
 Bell, Dana (1995)       Air Force Colors Volume 1 1926-1942, Carrollton:  Squadron Signal Publications  ISBN:  0-89747-316-7. 
According to Section 40.1.1.2 Color of MIL-STD-2161A (AS), the colors of this insignia are established as FED-STD-595 red 11136 white 17925 blue 15044. The visualization of the colors comes from http://www.colorserver.net/showcolor.asp?fs=11136+17925+)
NiD.29