when figuring out colors to get, with high end purchases, white is always a no-no for me with bags and shoes. Too much $$ and too high maintenance, so much that it will take away from my enjoyment of whatever is is i would buy. white leather is VERY high maintenance and i'd rather not have to worry about that.
I know many gals say tan, khaki, chocolate and black are all staples, but you really need to figure out which colors work best for you, IMHO. i find that a more redish brown is more favorable to a true chocolate brown for me. Tan doesn't work for my but cognac colors do. It's simply a trial and error thing. but you should always have a good black bag and a wicked pair of black shoes to go with them. I personally dont wear much of any colors and so subtle changes and tones and textures of neutral colors really do it for me. i have tried like hell to incorporate colored bags into my wardrobe, but it just doesn't work. all end up either for sale on ebay or i donate them. i just cant do the color thing and feel comfortable.
i also like a lot of bags, of which less would actually look good in my wardobe. when shopping, you really need to think about your most favortie things you wear, and if that possible purchase will work with what you have or compliment it. that's an important thing im just learning now. i have to think first and if the bag fits into my wardrobe, i'll get it. otherwise, it's just a style i like to look at and isn't practical for use.
and the whole silver and gold thing: i think if you match them, you can look more put together, but i dont think it's so much of a fashion-dont now-a-days.