Confetti in Janeway's hair
Confetti referred to small pieces of paper thrown in the air during a celebration.
In 2375, confetti was part of the celebration for the quantum slipstream drive aboard the USS Voyager. Some of it remained in Chakotay and Kathryn Janeway's hair after falling from the catwalk. (VOY: "Timeless")
Confetti could also be shot out of a confetti popper, rather than thrown manually. (SCO: "Asteroid Blasters, Part 4")