No diff between the XT Silver and Black (but IMO the silver is for fairy-boys if black is available
)
EDIT: ALSO.. sounds like you don't wanna spend tons of money but that's ok. STILL, I'd get a body-only XT, rather than getting it with the 18-55 kit lens. Instead, buy the 18-55 IS which can be had for between 100-200. Though one would think it is the same plus image stabilization, it actually has different glass and is far better for a low-end lens!