I own the black with the cedar interior but if your only looking at SSB and graphite I'd say definately go for the graphite. Before I even went to a dealership I looked on the net and thought SSB was a much nicer color but when I went it I didn't like it much. Don't get me wrong it's still a nice looking color but for me the silver trim doesn't stand out enough. My top 2 colors of black and graphite. I think of them as executive colors.
But really its all down to personal opinion so just go in and take a long look at them and you'll realise which color is for you.
Hope this helps