Adobe Color CC - Generates color themes that can inspire any project.
iWantHue - Colors for data scientists. Generate and refine palettes of optimally distinct colors.
Coolors.co - The super fast color schemes generator! Create, save and share perfect palettes in seconds!
Paletton - Color Scheme Designer
ColorExplorer - Simply put, ColorExplorer is an online toolbox for working with color palettes.
Color Palette Generator - Enter the URL of an image and find its color palette