Green’s Dictionary of Slang

ensign-bearer n.

[the colours of the face resemble those of the Union Jack]

a red-faced drunkard.

[UK]Eighth Liberal Science n.p.: He that looks red and colours in his drink, Ensign Bearer.
[UK]Grose Classical Dict. of the Vulgar Tongue ms. additions n.p.: Ensign Bearer said of a Drunken man who looks red, or hoists his Colours in his Drink.
[UK]Grose Classical Dict. of the Vulgar Tongue (2nd, 3rd edn).
[UK]Lex. Balatronicum.
[UK]Egan Grose’s Classical Dict. of the Vulgar Tongue.