What is "play the white man"

vb. (label en intransitive British informal potentially offensive) To act with honour, decency, and responsibility

__NOTOC__ Play the white man is a term used in parts of Britain meaning to be decent and trustworthy in one's actions. The similar American expression is "that's mighty white of you" with the meaning of "thank you for being fair".

The origin of the phrase is obscure. The colour white has long been associated with purity and virtue in English culture, but the racial sense of the expression may refer more explicitly to the administrators and soldiers of the 18th, 19th and 20th-century British Empire.