Who Can Use - WhoCanUse is a tool that brings attention and understanding to how color contrast can affect different people with visual impairments.
Site Palette - Get the essential colours from any website
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.
Color Palette Generator - Enter the URL of an image and find its color palette
Cron Color - Free web tool for designing color palettes and checking contrasts.
Kontrast - Check and adjust web element contrast in real time.