i need a site that has oil paintings on it and it tells you what colors to use?

Answer 1

I don't know any specific sites for oil painting, but http://www.deviantart.com/ has many types of art/artists on it. You might look around on there for some help. I know that many of the artists are more than happy to answer questions and help you learn something new.
Sorry I'm not much help to you, but maybe if you look there someone else will be. :-)

Answer 2

The choice of colours is yours, it's question of feeling and personality. What you should know is the concept of warm colours, cold and neutral and even if you decide to go for blue, for example, you can have all of those (Prussian blue, cerulean blue, indigo, French ultramarine etc.)
There is another rule you should know, it is aerial perspective. Some colours are "closer" and some reject the eye in the far. For example never use yellows in a background, I did the mistake and I had to correct it with a light violet glaze i.e. a red-blue tint.
I hope you'll find some answers on the site below, but artists have to find the answers by themselves, being painters or musicians etc.