Orange lightsabers have mainly been seen in Star Wars video games. For example, according to Screen Rant, in the "Star Wars: Dark Forces" video games, protagonist Kyle Katarn, who was once part of the Empire but then later joins the Rebel Alliance, begins using an orange lightsaber after training to become a Jedi.
Orange lightsabers were seen again in the 2019 video game "Star Wars Jedi: Fallen Order," which gave players the ability to choose their own lightsaber color, including orange. It's unclear what the color means, but Screen Rant points out that it could represent Jedi who were once part of the dark side.
There are many more lightsaber colors to exist, however, their exact meanings remain a mystery.