Green’s Dictionary of Slang

a red-headed person, esp. as a nickname or as a direct address; of black people, one with reddish-brown skin colouring.

[1858		Bell’s Life in Sydney 3 July 3/3: That red ’un was a little too flash].
1873		Wichita Eagle 11 Nov. in Miller & Snell Why the West was Wild 262: E.T. Beard was better known as ‘Red’ [...] He was about forty-five years of age, straight as an arrow, red hair, which fell in a profusion of curls upon his shoulders, and from which he took his name of ‘Red’.
1906		Barrier Miner 5 Jan. 2/4: [He] found a miner named Edward Robertson, known as ‘Red Ned’, hanging by a halter.
1913		Dakota County Herald (NE) 4 Apr. 3/1: I was trying to figure out my next move when Red Saunders hove into sight.
1919		‘Sax Rohmer’ Dope 34: Red Kelly wholly merited his sobriquet, for the man was as red as fire. His hair [...] was brilliantly red.
1927		D. Hammett ‘The Big Knockover’ Story Omnibus (1966) 296: At 9:10 Red O’Leary came out of the hotel [...] The fire-topped giant didn’t take us far.
1935		N. Algren ‘Thundermug’ in Texas Stories (1995) 69: OK, Red. You look like a white man, all right.
1940		W.R. Burnett High Sierra in Four Novels (1984) 302: You two beat it. I want to see Red a minute.
1953		K. Tennant Joyful Condemned 245: People were always putting themselves out for Red.
1967		M. Braly On the Yard (2002) 4: The vivid orange hair that had prompted some forgotten humorist to call him Society Red had long since faded.
1976		P. Conroy Great Santini (1977) 173: Let me go, Red.
1980		J.L. Gwaltney Drylongso 91: Red (a nickname frequently applied to persons with a certain reddish-brown cast of skin color).
2001		(con. 1975–6) E. Little Steel Toes 73: Whatcha starin’ at, Red?
2010		(con. 1973) C. Stella Johnny Porno 53: The redhead wore a tiger-print short dress with matching heels. ‘Big red,’ Kelly said.
2018		T. Pluck ‘Hot Rod Heart’ in Life During Wartime 102: ‘Fire her up, red’.
2021		J. Ellroy Widespread Panic 302: ‘Hi, Red. I knew you’d have a kicky voice’.