Hi Romelo1680:
You can go to the GM Heritage website to see what were the factory paint schemes and colors offered for your year truck. You should find a pdf of a 1985 brochure and spec sheets. If you have the service parts list provided by the factory (originally attached to the inside glove box door) this should indicate what the color code of your paint was originally.
I am not an expert on all the paint schemes for every year, but just looking at your photo I dont think the two tone color scheme for your truck is original.
Regards,
Henry