OCR-B is the monospaced face Adrian Frutiger drew in 1968 for ECMA and the world ratified in 1973 — the digits under every barcode, the two lines at the foot of a passport, a shape engineered for optical scanners yet still legible to the eye.
This system reads that machine-vision heritage as a scanner console: cyan phosphor characters glowing on a deep, dark teal field. Everything is fixed-pitch, tabular, and lit from within — a single luminous hue over an unlit ground, never neon clutter.