I can select only one swatch at a time in style dialog box. A second button would be nice. That way I would have the default swatch and my custom image shown at the same time in the style dialog box. I could have a picture of a face in one and the body in another. I find my self reloading the same pictures all the time.
What I do is to pick my palette of colors ahead of time and create a special image that has all the colors in boxes for easy selection. Saves time reloading the images and trying to pick out a teeny spec of color on an image.