Colors and Fashion

Apparently, I don't have much fashion sense. I think jeans and a t-shirt are a great outfit. Especially, if it's one of my race shirts. My favorite outfit is my PJ's.  At my sister's graduation, I wore black dress pants with a navy blue blouse that had white polka-dots without thinking twice. I was informed more than once that navy doesn't go well with black. Really? They are both dark colors and I thought they went together.  Another instance of my lack of style just happened today while I was out shopping for shoes to go with the dress I'll be wearing at Mrs. Conklin's 50th birthday party. The dress is white on the top and it's some sort of blue color from right above my waist to the bottom. I was looking for some kind of flat, closed toe shoe to go with it. I don't see the big difference between white and cream, but I was informed today that putting a white dress with cream shoes would be a bad idea. I just don't see how it's wrong. I don't look at navy and black together or white and cream together and see a disaster. It seems silly. Am I getting bad intel?