Site Palette - Get the essential colours from any website
Sketch Palettes - Sketch plugin to save and load colors into the color picker
Color Palette Generator - Enter the URL of an image and find its color palette
Colorion - Curated color palettes with search and tags support
Colour Contrast Analyser - TPGi's ADA Color Contrast Checker checks for helps determine the accessibility the contrast ratio of two colors for WCAG AA and AAA.
UI Colors - UI Colors is a tool to create, edit, preview, export and save Tailwind CSS colors.