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Why is School Bus Yellow?

Updated: Jun 30, 2020

National School Bus Chrome.  National School Bus Color. National school bus yellow.  National School Bus Yellow Color.  National School Bus Glossy Yellow
Why is School Bus Yellow

Working in the pupil transportation industry for some time, I have wondered why school buses are yellow. After researching and watching hours of YouTube myself, I concluded that there is not a single video uploaded with the correct answer as of the date this post was published. I hope this eventually leads to more accurate videos and published information.

Although the video above is good, and provides some helpful information, even this clip provided by Business Insider which was released just a few months ago isn’t quite accurate. In addition to my frustration, the answer found even on Wikipedia as of the date writing this didn’t fully answer my question.

So I researched the school bus history archives, and I came across the National Congress on School Transportation website, where I located the first edition of School Bus Standards which were produced in 1939. These Minimum Standards for School Buses were developed and approved by representatives of the forty-eight state education departments in a conference held on April 10-16, 1939 at Teachers College, Columbia University.

It was in this 1939 document that I found the original answer.

Why is School Bus Yellow?

The school bus is yellow for two main purposes: to provide both safety and economy.

The text reads. “National School Bus Chrome was adopted by the congress as the uniform color for all school buses throughout the United States. The first consideration in adopting a new uniform color was to provide safety which will accrue when, throughout the United States a school bus is recognized by its color. The second consideration was economy since manufacturers are forced to make additional charge for special orders.

Engineers of the United States Bureau of Standards prepared the samples and provided technical advice upon which the choice was made. The United States Bureau of Standards, Washington D.C., has prepared Federal Specifications. This color can be legally used in most states at once as few states have exact specifications and the majority of the present regulations are a general requirement for orange or yellow.

Even the panels on the front cover of this report represent the range of shades included within the Federal Specifications for National School Bus Chrome.”

You can also view all the National Congress on School Transportation's Past Publications from 1939-2015 (soon 2020) at the link below.

Interested in Buying School Bus Yellow Paint?

I found a few websites that sell one 12 ounce can of Rust-Oleum's brand of Industrial Choice for an alkyd enamel spray paint in school bus yellow with a glossy finish. It works on masonry, metal, wood, and plastic. It appears this item is restricted from shipping to California. This paint also dries in about an hour according to it's technical specifications. I should mention that it's also VOC and MIR Compliant, and can be applied within 50 Degrees to 100 Degrees Fahrenheit.

Important to note: These are direct non-affiliate links. Just trying to help you out and make your life easier, rather than collect a few sneaky bucks from you.

Amazon $11.97 & FREE Shipping. At the time of researching it's in stock. Usually ships within 2 to 3 days. And if ordered on June 28, 2020 it should arrive: July 8 - 10. It's also currently rated 4.1 out of 5 stars for customer reviews on Amazon.

Grainger $6.35 / each. If ordered on June 28, 2020 it would be expected to arrive Tue. Jun 30, or it would also be available for pickup Tue. Jun 30 with an estimated time after 9:00 AM. from the Grainger store nearest me which is 12 minutes away.

Walmart: $4.97 with a $5.00 delivery. If ordered on June 28, 2020 it should arrive by Wed, Jul 1. Pickup is not available. It's also currently rated 5.0 out of 5 stars with only 2 ratings for customer reviews on Walmart.

Lowes: Lists this product on their website, but when I typed in my zip code for pricing. A message said, "This item is no longer sold on". So I'm going to stop here and say, NOPE to Lowes.

My conclusion for buying school bus yellow paint: Even though I worked at Lowe's for a time that's simply not an option for me. Although I'm an avid Amazon Prime shopper and use it's television perks, sorry Amazon, not this time. As far as Walmart, I think it's silly to pay more for a delivery fee than the actual product so nope to this option, which leads me to my opinion of going with Grainger if I was going to purchase a can of school bus yellow paint. Compare and contrast the options for yourself. Pricing, availability, and shipping options might be different for you when looking into this. I just thought I would do what I can to help you out in being a smart consumer.

About National School Bus Chrome

According to Merriam-Webster, National school bus chrome is a "variable color averaging a vivid orange yellow that is redder, lighter, and stronger than bright marigold." The pigment used in the color National School Bus Chrome contained lead, a toxic, heavy metal. Over time the color for school bus has changed slightly. The color has changed names and formulas. It is now called National School Bus Glossy Yellow which is recorded as Federal Standard No. 595a, Color 13432. It no longer contains lead.

National School Bus Chrome

Chemical name: lead (II)-chromate

Formula: PbCrO4

Refractive index: alpha = 2.31, beta = 2.37, gamma = 2.66

Color Index (C.I.) PY 34

National School Bus Glossy Yellow

National School Bus Glossy Yellow is recorded as Federal Standard No. 595a, Color 13432 with both the National Highway Traffic Safety Administration and the National Institute of Standards and Technology.

The color 13432 is shown here:

The hexadecimal color code #f5a400 is a shade of yellow. In the RGB color model #f5a400 is comprised of 96.08% red, 64.31% green and 0% blue. In the HSL color space #f5a400 has a hue of 40° (degrees), 100% saturation and 48% lightness. This color has an approximate wavelength of 582.72 nm.

The federal standard is managed by the SAE. More information about the federal standard on

According to NHTSA, “Guideline 17 recommends that school buses be painted “National School Bus Glossy Yellow” and have other uniform identifying characteristics. The uniformity of school bus appearance helps motorists identify the vehicles as school buses

National school bus yellow:

According to the glossary under the terms and definitions section of the 2015 Revisions to the National School Transportation Specifications and Procedures as by the 16th National Congress on School Transportation, "National school bus yellow is the color defined in the publication “National School Bus Color Standard” SBMTC-008."

Appendix B: School Bus Body and Chassis and Specifications National School Bus Yellow Standard The color known as National School Bus Yellow (NSBY) is specified below.

School Bus Manufacturer’s Technical Council (SBMTC) as documented.

"National School Bus Yellow Color Standard SBMTC-008 (Source Document)


This standard defines the color for a newly manufactured school bus having “National School Bus

Yellow” by fundamental colorimetric data.


This standard is intended for use by manufacturers of school bus type vehicle body and chassis for

purposes of procurement, and inspection.


This standard applies to school buses.


The color “National School Bus Yellow” is defined as:

The color resulting from the colorimetric tri-stimulus data shown below.

The color known as National School Bus Yellow (NSBY) is specified below



Y x y

  • Centriod 40.2% .4882 .4205

  • Light Limit 41.8% .4882 .4198

  • Dark Limit 38.5% .4902 .4206

  • Green Limit 40.6% .4844 .4217

  • Red Limit 40.3% .4907 .4174

  • Yellow Limit 40.6% .4901 .4225

  • Blue Limit 40.2% .4828 .4162


The color “National School Bus Yellow” shall conform to the tolerance limits set in S4.


The colorimetric data should be used for acceptance testing purposes. However, accurate

comparison can be made only if values are obtained on the same instrument standardized under the same conditions.

Because this standard is not intended to be a performance standard for the paint and/or

materials used in the manufacture of the school buses, color matching procedures provided

in this standard cannot be used to determine conformity with this standard of school bus

type vehicles in use."

Other Great Resources For Understanding Why School Buses Are Yellow:


Thank you for coming with me on this journey through the origins of why school buses are yellow. It was an honor to discover that school buses are yellow to provide both safety and economy. I hope if you were in need of school bus yellow paint that I was able to be of service to you. I hope that you check out why I know so much about the school bus industry, it's history, and where this industry is headed. Learn more at Here's a quick preview for you because I think you will share this great resource as we are continuing to honor the safety aspect more now than ever before. Check out what's illuminating the Nation and helping keep thousands of students safer as they board their school bus. It's called the Gardian Angel school bus lighting system and it's something that'll tickle you pink, not yellow when you see what it does and all the amazing school districts that already have and will be getting this amazing technology.

Published 6/29/2020

Written by: Andrew Gardner, Director of Marketing, Gardian Angel, LLC.

Click here for more information about Andrew Gardner.

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