I am almost done my Jaster armor and after spending literally hours looking through the Open Seasons comic, I've chosen to go with a pewter rub'n'buff. The armor is the comics is darker than the Jango armor you see in the end of the comic yet has a very metallic reflective quality. The pewter is darker than than the silver rub'n'buff. I used flat black primer, wet sanded with 400 grit and then applied directly.
I'm using a red automotive paint that gives the illusion of red anodized metal for the shoulder bells.
If you really want to be accurate with this suit, be sure to use a red lens for the visor. I'm going to use a clear visor with red light gels over top to get this effect though ideally I'd like to get a red mirrored motorcyle helmet visor for this.
Hope that helps clarify.
Check out this image - definitely dark metallic.