Flux allows you to manage colour 'swatches', these are simply collections of colours that have usually be setup to complement each other. You can download swatches from colourlovers.com
To import a swatch into Flux, simply press the Import button on the palette, and choose the file to import. Flux can currently only import '.gpl' files.
Once you have imported or created a swatch, you can activate it by checking the box next to it.
The swatch will then become available in areas such as 'background-color' in the Inspector, making in simple to apply complementary colors to areas of your design.
The swatch will also be available in the AutoComplete feature of Flux.