I have several books of color palates lying around, and occasionally I'll flip through them for inspiration. Color sets a tone as much as layout and images that are used in a design, and this is one of the things that always takes the most time for me in building a layout. There are a couple ways I get started, one is to pick a single color as a base that I love, and build a monochrome scheme by changing the opacity on the color. usually dropping it in 25% increments and adding an additional one at about 10% to use as a fill for borders on images and such.