Material Palette - Generate and export your Material Design color palette
CSSGradient.io - As a free css gradient generator tool, this website lets you create a colorful gradient background for your website, blog, or social media profile.
Color Palette Generator - Enter the URL of an image and find its color palette
Material UI Colors - Color palette for material design
Klart.io Colors - A data-driven collection of beautiful color palettes 🌈
Picular - Google, but for colors.