Is there a way to save a brush once you have loaded several colours onto it?

For example, if I put plenty of paint down on the canvas (or on a scrap) so they are next to one another, then I drag my brush through, I can get nice effects with the next brush stroke because there are two or more colours on the brush. Rather than having to prep the brush like this every time (which is almost impossible to re-create anyway), is there a way to save the brush before using it so that I can use it repeatedly with the colour combination I just loaded onto it by dragging it through the different paints?