I was thinking of an object that will make a colorful shadow. So I tried lots of things, but most of them just made a plain black shadow. Then I saw my mechanical sharperner, its container is full so I removed it. I noticed that the container is clear and I thought that there is a possibility that I can make a colorful shadow out of it.
And then I tried, it worked! I got an amazing colorful shadow.
This shadow is my entry for the contest of @melinda010100