On Saturday, an orange hue emanated across the New York City skyline, cast by One World Trade Center. At the request of Gov. Andrew Cuomo, its 408-foot spire was lit up that color to honor the 800+ March for Our Lives rallies that took place across the world, calling for stricter gun control laws.

“The spirit of youth and activism seen and heard on the streets of our cities and throughout our nation today will carry forward — first tonight in the lights of New York’s highest tower and tomorrow in the change that must follow,” said Cuomo on Saturday. “The youth of this movement are angry at Washington and they’re angry at the lack of leadership, and they should be. And they’re saying if you won’t lead, we will lead.”

According to CNN, the use of orange as a symbolic color for the movement dates back to at least 2013, when 15-year-old honor student, Hadiya Pendleton, was shot and killed in Chicago while standing in a park. The shooters stated that they had mistaken the group she was standing with as members of a rival gang. In commemoration of Pendleton, her friends chose the color orange (“safety orange”) to honor her legacy and to call for stricter gun control regulations because it’s the color hunters wear to avoid accidents.

“Orange is what hunters wear in the woods to protect themselves and others from harm,” the organization Wear Orange explains. “Orange is a bright, bold color that demands to be seen. Orange expresses our collective hope as a nation — a hope for a future free from gun violence.”

This is not the first time One World Trade Center has served as a beacon for a cause. Previously, its spire was lit in green to support the Paris Accord, rainbow in honor of LGBT Pride and “Amazon Orange” as a bid for Amazon’s second headquarters.

Next, learn how the Lights on the Empire State Building are Determined and read about Spireworks, the App That Lets You Control the Colors of NYC’s Skyscrapers.