A set of 50 Lottery balls.
Using striped textures. Different colours are grouped in groups of 10.
There are two files. One used for the main image, and one containing all of the balls in numerical order. The main image is similar to the second file, only the balls are arranged to look more like what you could use them for. The second file has all of the balls in order for you to move and manipulate as you wish. I suggest using that one if you are going to design your own scene!
I know there are probably better, more advanced ways to do it, but a good old reactor simulation, will get you going nicely!
Mental ray materials used and textures included in the rar file. Textures are of a size that they won't slow your file down, but that the quality is good enough for a close up render!