Couple of days back I made a presentation I made to explain the concept of MapReduce simply. I have attached the slides here for anyone interested. Please note, this doesn't include animations. If you want to get a better feeling feel free to download the original version of this MapReduce presentation.
I have been using a color theme for the command line in both Windows and Ubuntu for sometime now and it has been really comfortable for the eyes. So if you feel tired or bored using the white on black try these.
Background Color: #3A4237 (in RGB this is 58,66,55) Text Color: White
It will give you this feeling of a good old chalk board. Here's a screen capture of how it looks.