half past a colored man, phr. — Green’s Dictionary of Slang

half past a colored man phr.

[i.e. midnight is pitch black]

(US black) half past midnight; usu. in answer to one who asks what time it is.

1944		D. Burley N.Y. Amsterdam News 16 Sept. 12A: I gimmed this fine green banana at half past a colored man a deuce o’ dims and darks on the cutback.
1958		Hughes & Bontemps Book of Negro Folklore 484: half-past a colored man: 12:30 A.M.