Thanks, everybody, for your responses. I managed to get the colors more or less how I like them. I didn't want to use very many different store-bought colors other than the primaries, plus black, and some brown I had from a long time ago. If I allow myself to buy any of the hundreds of different colors in the store, I worry I'll be handicapping myself and begin relying more on buying a bunch of different tubes instead of mixing colors, and mixing is what I have a hard time with, so I have to practice it. Again, thanks for your replies!