Most fleet owners wanted to keep cost low, and they decided they would not pay a dime more for fancy colours. Since then, most cabs in London have remained black for ease of identification.

The reason London's iconic Black Cabs are black is rooted in post-World War II economics rather than a specific law. Before 1945, taxis in London came in various colors, but in the lean years following the war, the Austin FX3 (and later the FX4) became the dominant taxi model. To keep production costs low and speed up delivery, the manufacturer supplied them in a standard "factory black" paint. Because black was the cheapest and most readily available color, almost all fleet owners chose it. Over the following decades, this became an accidental brand identity. By the time the Transport for London (TfL) "Conditions of Fitness" were modernized, the black color had become such a cultural icon that it was maintained by tradition. In 2026, while you can technically find London cabs in other colors (often covered in full-body advertisements), the "Black Cab" remains the legal term for a "Hackney Carriage" that can be hailed on the street. Even the new 2026 electric LEVC TX models are predominantly manufactured in black to honor this 80-year-old tradition of British "economical" design.