(NEXSTAR) — While we all associate green everything with St. Patrick’s Day, that wasn’t always the case. If a few things went down a little differently, you may be wearing blue to celebrate the holiday.

The day was originally a Roman Catholic holiday to celebrate St. Patrick, the patron saint of Ireland. According to Smithsonian Magazine, blue became the color of choice when Henry VIII, King of England, declared himself the King of Ireland in the 16th century. To mark the announcement, he created a coat of arms for Ireland that used the color blue.

With that as the color of the country, artists at the time often depicted St. Patrick wearing blue. In fact, it became such a thing that the shade of sky blue was named “St. Patrick’s Blue.”

In the 1700s, Irish immigrants in the U.S. started the first parade in honor of St. Patrick in New York City. So how did we end up with green?

Green has long been associated with the Emerald Isle. In the 19th and 20th centuries, we saw an increasing division between British royalty and the Irish people. Over time, green was adopted as the color of the Irish rebellion—and the shamrock became a key symbol.

The Irish flag is three blocks of color—green, white, and orange. Green represents the Catholics who rebelled against protestant England. Orange, on the other hand, represents Protestants—who do not venerate saints. The white block symbolizes peace between the two factions.

In the end, green won out. Some say it makes you invisible to leprechauns who will pinch you if they can see you.

Even though green is now associated with St. Patrick, the members of Ireland’s St. Patrick’s Cathedral Choir still wear the color blue on their robes. And some even choose to wear orange on St. Patrick’s Day—a peculiar historical throwback on a religious holiday named after a saint.