Green’s Dictionary of Slang

(Aus.) a half-caste; also as adj.

1905		Bulletin (Sydney) 6 July 36/2: The mistress had four, to keep the attendance up. One was fair, one was red-headed; the next was a brindle (quarter Chow, quarter Chingalese), and the fourth a nigger.
1910		Bulletin (Sydney) 6 Oct. 11/3: Attached to pretty well every black or brindle person of any cash tonnage at all in this country, is [...] the white-man hanger-on.
1926		K.S. Prichard Working Bullocks 94: Got too many children and grandchildren, black, white and brindle, to worry about Ted and his brats.
1954		(con. 1940s) T.A.G. Hungerford Sowers of the Wind 5: It’s all the same—black, brown, or brindle.
1959		D. Niland Big Smoke 30: The white women who never drew the colour-line when the black or brindle had money to throw about.