Green’s Dictionary of Slang

salt and pepper n.

1. (drugs) marijuana, esp. of poor quality.

[US]Mezzrow & Wolfe Really the Blues 219: I wrastled some shake-up last night with some unbooted wren, blowin’ salt and pepper till my hair hurts.
[US]Murtagh & Harris Who Live In Shadow (1960) 52: Jimmy felt himself a fine singer when he had the ‘salt and pepper’ in him.
[US]ONDCP Street Terms 18: Salt and pepper — Marijuana.

2. (US black) as a synon. for black and white, usu. in racial contexts.

(a) a mixed-race couple, thus friends or colleagues of different races.

[US]W.G. Smith South Street 266: For Kristin’s sake, Claude had made the supreme effort to control his temper. [...] Passing them, on the street, people frequently made comments: ‘Well, look at that! Salt and pepper!’.
[US]D. Ponicsan Last Detail 159: ‘Hell, Boston is full of sailors.’ ‘Yeah, but how many of them are salt and pepper, toting two .45’s in an AWOL bag?’.
[UK]Indep. 11 July 3: A former manager of a McDonald’s restaurant [...] told an employment tribunal in Reading, Berkshire, that white and black people were represented by the words ‘salt’ and ‘pepper’.
[US]J. Stahl Plainclothes Naked (2002) 124: Says it was two guys, a salt-and-pepper.
[US]S.A. Crosby Razorblade Tears 155: ‘Here’s the deal, Salt and Pepper’.

(b) a police team, usu. operating from a squad car, that consists of one black and one white police officer.

[US]L. Dills CB Slanguage.
[US]E. Folb Runnin’ Down Some Lines 252: salt and pepper 1. Police.
[UK]J. Morton Lowspeak.

(c) a black and white squad car.

[US]E. Folb Runnin’ Down Some Lines 66: The vehicles and flashing lights that identify their continuous presence in the lives of blacks (black and white, salt and pepper).

3. (US black) courage, cheek, audacity.

[US]‘Iceberg Slim’ Pimp 176: You got salt and pepper, kid.

4. the act of two men having sex with one woman.

[US]R. Price Ladies’ Man (1985) 262: I imagined them doing a Pat and Mike on her, a salt and pepper.