ColorHunt
Color Hunt is a free and open platform for color inspiration with thousands of trendy hand-picked color palettes.
Related Tools
Dribbble Color
Dribbble Color is a wonderful tool that allows you to display all dribbble shots, based on certain colors.
Adobe Color
A very useful free color wheel and color palette generator for designers and developers. You can also upload an image to get colors from it.
uiGradients
uiGradients is a community contributed collection of beautiful multi-color gradients, free to use on your next UI or design project.
Grabient
A great tool that generates linear gradients, with the ability to customize each gradient, and download the CSS gradient code.