The color known as National School Bus Yellow was designated as such by the 1939 National Conference on School Bus Standards. The National Bureau of Standards of the U.S. Department of Commerce assisted in developing this color and its color metric specifications.
At the 1980 conference, the colors in use were reviewed. A color standard was selected, slightly different from above, and specific tolerances were chosen. These tolerances will ensure a continuity of appearance from bus to bus, and within the same bus when different elements are finished or refinished at different times.
When it was determined that the use of lead and chromium in paint was a health hazard, the National Bureau of Standards of the U.S. Department of Commerce assisted the S.B.M.I. in developing their color standard No. SBMI-008, which further defined the tolerances to permit better definition of the color. Specifications for the standard color, with light and dark tolerances are shown below in tabular form.
COLORMETRIC (CIE) DATA
DESCRIPTION | REFLECTANCE | CHROMATICITY | |
Y | X | Y | |
Centroid | 41.5% | .5139 | .4434 |
V+ Light Limit | 42.9% | .5139 | .4427 |
V- Dark Limit | 39.8% | .5133 | .4422 |
H+ Green Limit | 41.6% | .5123 | .4368 |
H- Red Limit | 41.7% | .5168 | .4489 |
C+ Vivid Limit | 41.5% | .5188 | .4457 |
C- Weak Limit | 41.5% | .5095 | .4405 |
Neb. Admin. Code EDUCATION, DEPARTMENT OF, tit. 92, ch. 92, app A