Color Palette Generator - Enter the URL of an image and find its color palette
Site Palette - Get the essential colours from any website
Klart.io Colors - A data-driven collection of beautiful color palettes 🌈
Material Palette - Generate and export your Material Design color palette
Materialette - A material design color palette on macOS / Windows / Linux
Sketch Palettes - Sketch plugin to save and load colors into the color picker