Hi Martin, hi Marlene...welcome!
While the two are lovely, my -personal- vote goes to the silver one.
I prefer the color, it has lower kilometers, it has a lower price too. Someone has modified the front grill to the XLR-V style which doesn't really score a plus or a minus - again, personally. (I actually prefer the regular grill...don't ask me why).
That said, you might do well to investigate the registry here and study the rarity of the color combinations for the 2006 model year. By example and for good or bad, that may be the only metallic blue with an ebony interior in all of Europe. If it happened to be a 1 of 1, perhaps it has some additional value if that matters to you at all.
I do hope you have read through some of the threads here regarding some of the more detailed things to look for - I can think specifically that the hydraulic pump and electrics which reside in the trunk, left lower 'pocket', should be carefully inspected for any water stains or corrosion from retaining water from leaking trunk seals or similar.
Headlights as mentioned...exceptionally costly so their condition should be carefully checked, noting any burn marks on the driving light lenses.
Taillights - check that all the strips of the LEDs do in fact illuminate.
The high-mounted brake light too however those are still readily available and actually not even terribly expensive.
Signs of shock absorber oil leaks. At around USD400 per corner... that does add up unfortunately.
I'm sure I'm forgetting things and hopefully some other members here will reply with some other points to help you make your choice. One or the other...they are lovely cars indeed.
Have fun and greetings from Canada,
Gord
