Image Colour Transfer - A free-to-use browser-based application that allows an image to be recoloured to match the colours of another image using novel methods.
Color Palette Generator - Enter the URL of an image and find its color palette
Colores - Find color palette ideas via image search
Material Palette - Generate and export your Material Design color palette
Alembic ⚗️ - A Sketch plugin to extract a color palette from your images
ColorFavs - Generate color palettes from images, urls or randomly