My 6p worth to the OP:
(1) Beige looks great but is a sod to keep prestine. Looks a shiny yellow, especially the driver's seat, after 6 months use. Don't wear Blue Jeans as you'll stain the seat bottom and have a two tone seat! Therefore, most impractical and not good for re-sale.
(2) Black leather with a Black car is pretty depressing. Like a hearse! Need to specify a sunroof to lift the mood. Extra expense.
(3) Coral Red Leather is the best. It's not a bright Red and looks very chic with a Black car or with nearly every exterior colour, except Red.
(4) Choose a different exterior colour as Black is tres, tres difficult to keep clean. Shows up swirl marks and scratches very easily. As impractical as a Beige interior.
(5) Therefore, a Black car with a Beige interior is totally impractical IMVHO. A double whammy!
(6) A Black/Beige car perfectly suits your Forum Name colour-wise but it could promote your early death from cleaning!
Superman F30 EBII 330d sDrive M Sport//Coral Red Hippo Hide Chairs.