I have Ti. Silver, Light Grey Intererior, Antracite Maple Trim.
My opinion on color is that if you car will see a lot of use (friends,dogs,bad weather,kids) I would go with a black interior.
Keeping a grey interior clean takes more time and the dirt shows up immediately.
My car is usually driven by one person (no dogs, kids, bad weather). It still needs to be vacuumed at least 1 time per week, more often if leaves and other junk has been tracked into the car and the light grey mats have to be shampooed 1-2 times per month, especially if any amount of grease/oil has been tracked into the car.
My 2c. Buy what you like.
2004 E60 530is, Delivered 12/12/03, TiSilver/LGrey, PP, SP,PS, PDC, ACC, FRS, Step, Xenons, clear bra, body colored rear inserts. (Retired, 1983 henna red 320is)
2004 Corvette Z06 Commemorative Edition