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Why Is the Underside of Your Hat Brim Green?

By Taylor James


Updated on

Whether you’re a hat lover or not, you may have noticed that hats are sometimes different in color than their undersides. Also called under-brim or under-visor, the underside of hats is usually green. Is there a specific reason behind it, or is it a style preference?

The underside of your hat brim is green because it has a soothing effect on the eyes. It takes the glare off the under-brim to give the wearer a better and more comfortable vision, especially in high light settings. Other colors such as grey and black have similar effects to improve performance.

Read on to learn about different theories behind the color of hat under-brims and why other colors are also common.

Different Theories Behind the Green Under-Brims

Several theories suggest why the colors of the underside of the hat brim exist, with the first theory being that bankers and accountants wore green eyeshades and covered their desk lamps with green shades. 

Another possible reason is that green is the easiest color on the eyes because the retina can perceive it more easily than other colors in the color spectrum. This restful effect on the eyes is especially useful in places with harsh lighting.

For the same reason, early sunglasses also used green-tinted lenses to block the glare and soothe the eyes.

Today, most baseball cap manufacturers produce green under-brims, because they believe green reduces the glare reflected off the brim, especially during daytime games. So, the players have less strain on their eyes.

Another theory is that it was just a branding decision made by New Era, a leading baseball cap manufacturer, to make their hats easily identifiable only by looking at the under-brim color. However, other brands started to make green brims after the New Era. Check out these New Era baseball hats on Amazon.

women wearing baseball cap with green brim
@alexgoldman via Twenty20

Other Colors Used in Under-Visors

The mainstream belief until the 1980s was that green is more restful on eyes. But it turned out that grey does a better job of absorbing the glare than green. New Era started to make green and grey under-visors and gave baseball teams the option to choose.

In the 1990s, most teams switched to grey, with the Cincinnati Reds being the first team to make the transition.

In 2007, New Era made another change to their under-visor colors and went for black. Again, the primary reason was to reduce strain on the players’ eyes. This change and other improvements in material and design made the hats more comfortable and performance-ready.

Other colors used in hat under-brims are pink, white, yellow, blue, and matching brim and outside colors. However, no color works like green, grey, and black in reflecting the glare of the hat’s underside. Read more about hat color considerations in this article.


Read this article to discover why baseball caps were invented. The reason the underside of your hat’s brim is green because it’s one of the most effective colors in reflecting the brightness of the brim in high daylight conditions and gives baseball players more visibility to reduce stress on their eyes.

Grey and black are also possible because they have the same effect.

However, another possibility is that New Era, which was the first hat manufacturer to use the color green, used it to make its brand stand out.

Ever wondered what hat brims are made from? Find out here.

About Taylor James

As Philip Treacy once said, “How a hat makes you feel is what a hat is all about.” And on that note, I hope you enjoy your hats and find the site useful. Learn more about Hat Realm's Editorial Process.