Restoring the original color of metal and chainrings I bought a used bike and I want to pimp it up and make it cleaner. I found rust on the chainrings and I would like 1- to remove it and 2- get the original color of the metal back. How to do that? Here are the pics of my bike: Painting a bike with minimum cost

p.s. I need to do that in the cheapest way possible because I'm a poor student.
I doubt you're going to be able to get the original color of the metal back, and the rust is pretty much aesthetic, so don't worry about it.

If you really want to try this, you'd likely need to take the chainrings off the bike (which may require a crank puller, which you likely don't have), use something like phosphoric acid to remove the rust, then either paint them or powder coat them or something to prevent the rust from coming back. By the time you've done this, you could have probably bought a cheap new/used crankset that was rust free to begin with. 

Or, you could just leave it and not worry about it, like a normal person.