VivaldiFox - An add-on that allows colouring Firefox in a Vivaldi style fashion
Klart.io Colors - A data-driven collection of beautiful color palettes 🌈
automaticDark - Time-Based Theme Changer - Set Firefox to change the UI to a dark theme during the night and change back to a light theme during the day!
Color Hunt - Curated collection of beautiful colors, updated daily
Dark Reader - Reduce eye strain in your browser with this extension that provides a dark theme for browsing.
Material Palette - Generate and export your Material Design color palette