CHICAGO (CBS) — You’ll be seeing a lot of orange in Chicago and in cities across the country on Tuesday, as part of National Gun Violence Awareness Day, inspired by the friends and family of a high school honor student slain in Chicago two years ago.

The “Wear Orange” movement started in Chicago, and what’s being called a party for peace Tuesday afternoon will make sure it keeps going.

Hadiya Pendleton would have turned 18 years old on Tuesday, and would have graduated from high school in a couple weeks. Friends, family, Chicagoans, and people from all over the country will wear orange in her honor, and to help bring awareness to gun violence.

“I think the fact that our heart hurts so much, that’s the reason we’re motivated to get into the movement,” her mother, Hadiya’s mother, Cleopatra Cowley-Pendleton said.

“Hadiya’s friends, they wanted to make people more aware gun violence exists,” said Hadiya’s father, Nate Pendleton.

Tuesday was the first ever National Gun Violence Awareness Day, inspired by the life of Hadiya Pendleton.

The honor student was shot and killed in January 2013 while hanging out with friends at Harsh Park in the Kenwood neighborhood, not far from President Barack Obama’s home.

On Tuesday, her friends and family will not only wear orange, they’ve also organized a community event called “Wear Orange Party for Peace,” from 3:30 p.m. to 8 p.m. at Harold Washington Playlot Park, at 53rd Street and Hyde Park Boulevard. The rally will include food, live music, slam poetry, and a photo booth.

Even if you can’t make it, no matter where you are Tuesday, you can join the campaign by taking a picture or selfie, and using the hashtag #wearingorange.

Orange is significant because it’s what hunters wear to keep others from shooting them. It’s a glaring warning sign to not shoot. That’s the message organizers are trying to convey: don’t shoot.