The phrase "black pinstripe" refers to a pattern or design on clothing, usually suits, where there are thin black stripes running vertically. Full definition
First, choose from two colors: white with black pinstripes, or black with white pinstripes. (dresshead.com)
Last summer I bought a gently used Anne Klein black pinstripe skirt suit with a silk lining for $ 4 and a brand new white skirt suit for $ 2 (needed a bit of tailoring, it was a bit big for me) from the Salvation Army. (thecollegeinvestor.com)
A black and white polka - dot camisole + black pinstripe pants or skirt + a jacket / blazer. (yourtrueselfblog.com)