If you've ever designed digital products, you might have had to play with a lot of colors. There's a lot of great tools and resources out there to help you with your coloring needs, but Colour Lovers is quickly becoming a favorite of mine. I've found a lot of great palettes that brought together a number of different elements more elegantly than I would've pictured otherwise. Great time saver and inspiration maker.
The Design of Influence: How to Craft Products that Move People