Black it is (full circle, but now said with confidence!)
Thanks to the link to that e90post.com thread - seems like DSB is fairly rare (I know it's recent) and 80% of owners choose the lighter interior colors.
Saddle was really starting to grow on me, then I used the "build your own" again and saw the interior view with the mix of colors. For me DSB and dark walnut are non negotiable (the walnut is an old Triumph 2000 feature, I think old Jags had it too).
In the interior saddle would look good with the black or aluminium insets, but with my insistence on dark walnut there's just so many colors going on - saddle, black, dark walnut - that it loses it's cool. Two interior colors cool, three - too many.
To all those who recommend cream or oyster - I have to agree with you - this is the most logical choice and looks good; but I see these combinations a lot. I want to be a bit unique, but coral is pushing it too far (for me).
So I'm with MMME30W, TJG and MP3_E46. It remains black.
I may not have changed my mind from this thread - but it has helped a lot. Yesterday I started out thinking "black, mmm, maybe" now I'm locked down on black.