uiGradients is a community contributed collection of beautiful multi-color gradients, free to use on your next UI or design project. You also have the ability to download the CSS gradient code.
Color palettes generator, ColorSpace is a space for everything that has to do with color palettes and gradients.
Dribbble Color is a wonderful tool that allows you to display all dribbble shots, based on certain colors.
The super fast color schemes generator! The Coolors app allows you to create, save and share perfect color palettes in seconds!
A great tool that generates linear gradients, with the ability to customize each gradient, and download the CSS gradient code.