If youre choosing between black and silver, its gotta be silver every time + black gets to look dirty very quickly.
My personal choice would be Topaz Blue with black or grey leather, or if you want to push it have it custom painted in the E36 M3 colours Estoril Blue or Daytona violet or Techno violet, any of those 3 would look unbelievable, especially with grey or black leather... if youre a little out there Laguna Seca Blue looks very awesome, flash too
cheers,
jay