user: Mark puts his blue basketball in a wooden box. Mark doesn't know it, but this is a magical box, which changes colors of things that are left inside. After a few minutes, the basketball turns green. Mark observes what is happening and then closes the box. What does Mark observe when he opens the box?

assistant: Mark opens the box and can see that the the color of the basketball is still green. The magical box had done its work, altering the hue of the basketball from its original blue to a vibrant green.