Quoting the wiki (ew, fandom!)

The Pixar Ball (also known as the Luxo Ball) is a yellow ball with a blue stripe and red star that first appeared […]!

So… yeah, clearly not its name, not any more than its name is "Pixar"

It's the Luxo ball as in "the ball from the Luxo film" not "Luxo the ball". Luxo [Jr.] is the lamp.