Yellow

School bus yellow is a color which was especially formulated for use on school buses in North America in 1939. The color is now officially known in Canada and the U.S. as National School Bus Glossy Yellow and was originally called National School Bus Chrome. The pigment used for this color was, for a long time, the lead-containing chrome yellow.

The color was chosen because it attracts attention and is noticed quickly in peripheral vision, faster than any other color. Scientists describe this as follows: "Lateral peripheral vision for detecting yellows is 1.24 times greater than for red."

In April 1939, Dr. Frank W. Cyr, a professor at Teachers College, Columbia University in New York organized a conference that established national school-bus construction standards for the U.S., including the standard color of yellow for the school bus. It became known officially as "National School Bus Chrome". The color was selected because black lettering on that hue was easiest to see in the semi-darkness of early morning.