The word " gringo " did not originate during the Mexican–American War (1846–1848) as a corruption of "Green, go home!", in reference to the green uniforms of American troops. The word originally simply meant "foreigner", and is probably a corruption of the Spanish word griego for "Greek" (along the lines of the idiom "It's Greek to me "). https://en.wikipedia.org/wiki/List_of_common_misconceptions_about_arts_and_culture#Language