My palette is, and has been, the same for the most part for over 30 years. Every now and then I add something or other, but mainly it is called a traditional limited palette. It's 4 colors, the primaries, red, yellow and blue, and titanium white and every color is mixed from these. It's also what I advocate in my classes so that students don't have muddy colors. There is a rule of thumb, that you shouldn't mix more than 3 colors, which is generally true because it almost always turns to be the same “mud".
My primaries are Cadmium Red Medium, Cadmium Yellow Light, and Ultramarine Blue...every now and I use a split palette which is of each primaries but generally most paintings are done with the 4 colors.
The ground color of the canvas is generally painted a red tone and the overall tones of certain paintings vary due to plein air or in the studio (plain air being outside which is brighter and colors are applied darker).