strip/sand/prime first. To do that, remove the tensioner, motor/belt/wheel stuff and mask off the rest. There are several good tutorials available. If that is severe corrosion on the bottom consider complete disassembly. Find a magenta you like locally(which shouldn't be a problem) then go for it! if however you want FLAKE, then try Roth rattlebombs, at:
http://www.rothmetalflake.com/rattlebomb/flakes.html and if you try the Freakin Fuschia then we want PHOTOS. Below is my magenta baby done with microflake and candy. PLEASE excuse the dust- I had no idea it would show up so badly.