Science Buddies: "Ask an Expert"

So this actually isn't a science project question, but a science question in general and I can't find the answer anywhere else.
This morning I was using snapchat on my phone, when all of a sudden, the front camera (that was facing my pillow) started changing colors! There is nothing wrong with my phone and this only happened on the front camera, ONLY while facing the pillow. It didn't change colors and when I faced it towards me or anything else in my room, just the pillow. I even caught a video of it!
Anyways, I was wondering if this is due to waves in the phone..? I just want to know what the science is behind this. I couldn't find a tag on the pillow, so I don't know what it is made out of. It's just a normal pillow with a faint light green pillowcase.
If you can answer this question, thank you so so so much!

Hello. A very interesting question. Unfortunately, this forum is only for students working on science fair projects. There are other forums on the web that can help you with your question.

Good luck!