You will still be deciding by the time every colour has been spelled out.
Go for the colour that marks the champion days of a maker. In this case, GULF BLUE. There's no substitute, there's no choosing. Here's an example i found:

 

Rasta, did you buy that Porsche? Have you decided on the color?

 

Carbon Black. It is a color available on E46 M3's and E39 M5's. It is gorgeous. Looks almost black with a hint of midnight blue in it. Darker than the factory Porsche Midnight blue metallic.

 

I vote BMW Carbon Black too! It is a great color that looks black most of the time. Depending on how the light is hitting the car, it looks like a really deep dark blue. It is truely awesome in person.

 

how about this?

 

That is one butt ugly color!

 

are these better?

 

I rode in a tank that color

 

That purple car is interesting...not for me though. Probably changes color radically in different light.

 

Being biased , i vote beige-grey
my 73 factory color.

 

Check out the 997 on this link.

http://www.911flatnose.com/