When you've shouted "Rule Britannia", when you've sung "God Save The Queen", When you've finished killing Kruger with your mouth; Will you kindly drop a shilling in my little tambourine For a gentleman in khaki ordered South?
The English Government for a long time has used a type of pigmented dope cover, khaki colored by iron pigments and lampblack, which is called P. C. 10.
2007, Yuji Matsuki, American Fighters Over Europe: Colors & Markings of USAAF Fighters in WWII, page 4, ISBN 0890247110.
At the end of World War I, the U.S. Army Air Service painted everything khaki. This khaki was practically the same as British PC10 and can be considered the basis of the later olive drab color.
2010, Martin Windrow, French Foreign Legion: Infantry and Cavalry since 1945, page 52, ISBN 1855326213.
In these notes we have used the British rather than the US terms for colours: i.e. 'khaki' here means the drab brown - US 'olive drab' - used for woolen uniforms and 'khaki drill' for the pale yellowish tan - US 'khaki' - used for lightweight summer/tropical dress.
Op. cit., page 56
The very loose seroual trousers were made in both sand-khaki drill, and in winter-weight khaki wool for wear with the M1946 battledress blouse.