Originally Posted by EdwardL

When you order the M sport package I believe you can request black or silver. If you don't put in a request you just get the colour the factory picks. I don't know how they pick the default colour - with my carbon black M sport, roof rails were black by default.

Sorry no idea on costs and install but I'm pretty sure you can buy original BMW individual roof rails in black - a call to your dealer or google should confirm that.