KGamut 2.0 - It analyzes the colors of images - here you can see the region of colors used by Lorenzo in this amazing sunrise illustration. I've been having fun using only these colors in some painting studies so download them below. You don't need, and possibly shouldn't use, every color all of the time to make a stunning piece. Try out limiting your colors according to gamut range/mask such as this. Also try dropping paintings both digital and traditional, movie frames etc. into the KGamut tool - I am always surprised how few colors and saturation are used on some amazing images!
More on this topic: Gurney Journey
Artwork by Lorenzo Lanfranconi