Green screening

I made this little youtube clip about one way of using Google to flip your class for a specific purpose, but the reason I want to tell you about it, was that it was my first attempt at green screening. The green blob behind my head is in fact the shadow cast from the light in the lounge. The shadow was slightly different green to the green that I removed. However, it generally came out better than I had hoped otherwise. I whipped down to the lake and took a short video of the lake and superimposed myself on top of that after I removed the green background. I might try to experiment a bit more on this. I read somewhere that blue screening works just as well. Has anyone tried that?  Would love to hear more.