RickyE said:
This is the first time I have ever used mineral spirits. It was a gray color. Is mineral spirits suppose to be clear or is it a white color because the bottle I purchased I noticed it was a white color after I opened it.
I think you might have a bad batch of thinner, too. I have never seen mineral spirits as anything but clear, out of the can or bottle. If you clean your brushes in a jar of it, the liquid will be cloudy, till the particles of pigment settle out, but then the liquid will be clear again. Same goes for a batch of wash that you might make-if you put the thinner in a jar, add some paint and stir, it'll become opaque and the color of the paint, but if you let it sit long enough, the pigment will settle to the bottom and the liquid will be clear.
I don't usually pooh-pooh Walmart, because I buy some supplies there, too, like my primer, but I usually buy my mineral spirits at the hardware store. The stuff you get at Walmart should be of similar quality, but beware of something that is really cheap, because it might be really cheap.
As far as the oils go, yeah, I'd look for oils at a craft store, at least, like Michael's, AC Moore or HobbyLobby, or at an art supplier, like Dick Blick. It's worth it to pay for top-grade oils, because they will last you a long time, and as Chris noted, the cheaper oils have pigments that are more coarsely ground than the higher-end oils do. Same goes for acrylics, by the way. I have some craft store acrylics, which are OK from some applications, but their pigments are so coarsely ground that they're not very good for things like painting a uniform in 54mm.
Hope that all helps!
Brad