Gradient by ShopFactory is a great tool for finding wonderful gradients, to use in your next project. It allows you to manipulate the gradients based on color, pigment and lightness.
Color Hunt is a free and open platform for color inspiration with thousands of trendy hand-picked color palettes.
The super fast color schemes generator! The Coolors app allows you to create, save and share perfect color palettes in seconds!
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.