Used November 1926-July 1940 by USAAC and USAAF, leading edge of blue stripe was in line with the hinge and any area of rudder ahead of the hinge was left in airframe color.
Proportions based on information from  Bell, Dana (1995)       Air Force Colors Volume 1 1926-1942, Carrollton:  Squadron Signal Publications  ISBN:  0-89747-316-7. 

Colours based on (40.1.1.2 Color of MIL-STD-2161A (AS), as FED-STD-595 red 11136 white 17925 blue 15044. Color visualization as per http://www.colorserver.net/
Own work
NiD.29