Here’s a tip for anyone wanting to store swatches for polypainting – in the ‘color’ palette in zbrush, click SysPalette and store a swatch there in the OS box that opens… 
The Canvas Color Palette plugin is a much better solution as you can have the color swatches right on the canvas where all you have to do is move your cursor over the swatch and press the ‘C’ key to change the color. You can also save your color schemes in case you have to carry on at a later date or if you need more than the 10 colors which is something you can’t do with the System Color Palette. Works in version 4R3 too.
well thats handy. thanks.