E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Red Button (A).
A mandarin of the first class, whose badge of honour is a red button in his cap.
An interview was granted to the admiral [Elliot] by Kishen, the imperial commissioner, the third man in the empire, a mandarin of first class and red button.Howitt: History of England, 1841, p. 471.