Every single school bus in the United States is painted the exact same color — a hue officially known as "National School Bus Glossy Yellow" — but it wasn't always that way. A century ago ...

Their solid frame ... standards for school buses," a set of 44 rules all buses should adhere to. This included details like length, aisle width, and even the iconic yellow color.

The yolky exterior color, called National School Bus Glossy Yellow, has remained the go-to shade since 1939. Buses are ...

School buses have an enviable safety record, thanks in part to their bright yellow color. David L. Ryan/The Boston Globe via Getty Images ...