Green’s Dictionary of Slang

white-headed adj.

(Aus.) angry, indignant.

[Aus]Gadfly (Adelaide) 25 Apr. 20/4: ‘Wot ’ave I done?’ I asks, indignant. / ‘Never knew yer to ever do anythink,’ ’e replies, sarcastic. ‘But don’t git white ’eaded; I’m not torkin’ erbout that jus’ now.’.