I'm gonna hang on to this idea, but I have to say, I saved a whole bunch of egg cartons before Christmas so I could store my ornaments this way. and NONE of my ornaments fit the egg carton compartments. :P Goodbye, egg cartons.
If you want to keep all your ornaments in the same container, but sorted by color, use clear gallon bags from your kitchen. Then next year, it'll be super easy to assess your stash — and if you should.