Site Palette - Get the essential colours from any website
Color Palette Generator - Enter the URL of an image and find its color palette
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.
Material Palette - Generate and export your Material Design color palette
Who Can Use - WhoCanUse is a tool that brings attention and understanding to how color contrast can affect different people with visual impairments.
Sketch Palettes - Sketch plugin to save and load colors into the color picker