what color should the sun visors be

Are you trying to be "correct" or just asking for personal preferences?

Usual (sometimes unusual with Ma Mopar) rule of thumb is that they match UDFs, dash and everything above (pillar moldings, headliner, etc.) but of course, you can go any direction you want. What's nice us that the part(s) in question are easy to acquire/change out if one day you feel black and the next day white. Either way, have fun.