A colour palette in painting/photo editing programs is a completely different animal from the colour wheel. Think of the real life painting analogy - your palette is what you have definitely laid out for painting and you choose from there with your paint brush, your colour wheel is where you decide your tones, hues, etc, and eyeball it. If you're thinking of a mixing area like Painter in ArtRage, you can actually use the canvas itself and eyedrop from there.
Also you can hide the pods to make more room by using Tab on your keyboard on pc.