The reason why there are 256 RGB color values -- and not, for example, 1024 -- is that Gimp was programmed for 8 bit color channels. In most cases, 16 million colors is quite satisfactory, but there are certain highly specialized image manipulation programs that can handle 16 bit color channels. There is also a new version of Gimp under development called GIMP HOLLYWOOD that will include 16 bit color channels. In this book, we will focus on 8 bit (256 value) color channels since that is what you'll work with in Gimp.