At my dining hall, we all draw pictures and write things in permanent markers on the trays. This is lots of fun, but the colors fade after a while (some much more than others).

Is there some good way of protecting the colors? Maybe some sort of lamination?

It needs to be easy enough that we can apply it while still in the dining hall.

Thanks so much!
It's a fun part of our culture (college dining hall), and the administration is happy letting us decorate the trays.