Green’s Dictionary of Slang

beige adj.

1. (US black) a light-skinned individual.

[US]D. Burley N.Y. Amsterdam News 7 Dec. 20: Imagine a duo of ‘beige’ chicks bringing Georgia to mayfair.
[US]D. Burley N.Y. Amsterdam News 11 May 19: Uncle is eye-balling the beige chick.

2. (US) deeply tedious, very bland [the perceived blandness of the colour beige].

Dan Burley ‘Back Door Stuff’ 30 Oct. [synd. col.] That midtown beige king of the chicks has gone underground.
[US]Eble Campus Sl. Mar. 1: beige – ordinary, plain, drab, dull.
[US]P. Munro Sl. U. 34: My date talked about his stamp collection the whole night. What a beige personality!
‘Valley Girls’ on Paranoiafanzine 🌐 I’m sure that there must be just, like, a million marvs there, like, totally beige dudes.
[US]A.R. Favale Into the Deep 112: hrist was leading his mulish, plodding church out of the gloom of patriarchy and into the beige radiance of egalitarianism.

In compounds

beige flag (n.)

(juv.) an indicator of eccentricity.

Axis Parents’ Guide to Teen Sl. 🌐 Beige flag = Somewhere between a red flag and a green flag, this refers to a behavior or personality trait that is neither positive nor negative, just a little quirky or strange.