The first traffic signals were not red, yellow and green. ... in the 1840s the British railroads adopted a flag, ... stoplights are always arranged with red on top and green on the bottom.

On the yellow middle stripe, where Ethiopia’s Lion of Judah symbol then sat — replaced by a blue disk and gold star on Ethiopia’s modern flag — Okoh placed a black star.

The banner, with its horizontal red, black and green stripes, was adopted by the Universal Negro Improvement Association (UNIA) at a conference in New York City in 1920. For several years leading ...