I will be posting a palette set-up with pic over the next few days in response to a question from Paul (capeannpainter) here's my color line-up:
2 yellows: one light and bright, one dark. my choices: cad yellow light, cad medium, yellow ochre, raw or burnt umber
2 reds: one light and bright, one dark. choices: cad red light, grumbacher red, alizarin crimson
2 blues: one light and bright, one dark. choices: cobalt blue, pthalo blue. i rarely use ultramarine except to mix a violet.
other colors: burnt sienna: the only dark orange there is.
green: pthalo green and viridian. i only use these when i can't mix the color from the above blue/yellow choices.
titanium white, original formula pre-test (grumbacher)
black: ivory for a cool palette, mars black for a warm palette. i rarely use black, but it has its place.
when i start i determine my palette by what is before me.
and once again, everything you might want to know about, mixing and a bit more, I recommend Helen Van Wyck's Color Recipes. you can click through to Amazon.com via this link and i will get a few pennies should you order, or order your book through your local booksellar. My local bookstore is The Bookstore on Main Street in Gloucester MA, tell them Debbie sent you.