A bag of elastic bands in varying widths can be an Easter egg decorator's best friend.

All we did to make this egg was to randomly wrap the egg in rubber bands, then dip it in two different colors (in this photo blue and red), removing a few bands with each new color. Since we started with a plain white egg, we ended up with red, white and blue bands.

Admittedly, getting the bands to stay on the egg is a bit tricky, but it's not impossible if you're careful. Don't try to get the bands too tight as this causes them to simply roll off. The photo below shows the egg above, before it was dyed.