Hey Guys, here are the colors I have in my watercolor palette. I also use these exact same colors for oil painting.
There are 15 colors total. If you only wanted to use 12 full pans, I would remove Raw Umber, Cobalt Blue, and Ultramarine Violet. I really don't need the Sap Green, but I like to mix it with Cadmium Red for some really nice earthy reds. For you Munsell enthusiast, a low chroma yellow red. If your not familiar with Munsell terminology, it basically means a greyed yellow red, at a particular value. Could be a light greyed yellow red, or a dark greyed yellow red.