St. Patrick's Day is coming up on Sunday, March 17th and many folks will be wearing green to avoid the inevitable pinch. But where does that tradition come from?

While it's not an official holiday in most countries, St. Patrick's Day has been celebrated in the U.S. since the 18th century. Some reports state that the color blue was the first official color but that was changed to reflect the Irish flag and its nickname, which is the "Emerald Isle".

It is custom to wear green now on the holiday, especially if you don't want to get pinched.

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Why do you get pinched for not wearing something green on St. Patrick's Day?

After doing some research, there are a few different reasons. However, the most popular reason was because of those little dudes and the pots of gold they possessed. That's right, I'm talking about leprechauns.

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As the tradition goes, you're supposed to wear green to defend yourself from leprechauns. Wearing green makes you invisible from the leprechauns. But, when you don't wear green, people are supposed to pinch you as a reminder of the mayhem that leprechauns can cause.

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Aside from those pesky leprechauns, you should also wear green to display your Irish pride.

READ MORE: St. Patrick's Day Weekend Crawl At Heffs

So whether you're trying to fend off leprechauns or just show a little spirit for the holiday, make sure you have your green on this and every St. Patrick's Day. Or deal with random people coming up to pinch you all day.

Happy St. Patrick's Day!

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Gallery Credit: Chaz