The Sig Red was b-e-a-u-tiful!! I may be mistaken but, the shade of red did look different (a little darker?) than the original, hand-painted sig red beta from the factory event (and which is in Geneva right now). Of course, the cars were parked at the edge of a garage and it was a very overcast day so, that may have something to do with it.
I'm in the general production queue and don't have a shot at it but, my wife couldn't take her eyes off of the Sig Red!
For the general prod folks, here's my ranked choice of external colors (based on the sig cars on display as well as the design studio and paint chips in the store):
1) Blue - simply stunning! The car will really stand out on the road!! I'm getting this and the family's voted unanimously in favor of it!
2) Silver/Green - a tie! The Silver sig looked really good in person. The Green - if the design studio colors are accurate enough - looked very good too.
3) Pearl White - worth the $1,500 upgrade if you were considering the Solid White.
4) Grey - looked good in the design studio; a darker shade of Silver.
5) Brown - if that's your thing (and I got yelled at by my wife - who still sulks about my choice of Brown for her Mini Clubman - for even trying it out), it looked okay but, maybe, I'm biased against it already.
6) Black - bottom of the barrel in my opinion. All the beautiful and sometimes subtle lines of the Model S get lost in the 'black crush' (a la details in dark scenes on older LCD HDTVs).
Again, some of these impressions were from the design studio so, take this with a grain of salt.