Drop - Beautiful color picker with Touch Bar support
Just Color Picker - Free portable colour picker and colour editor for web designers, photographers, graphic designers and digital artists. Supports Windows and macOS.
Colordot for iOS - A color picker for humans.
Pickr - Flat, simple and hackable color picker.
Pixie - Pixie is a free, open source web application that will help you quickly create your own website. Many people refer to this type of software as a content management system (cms), we prefer to call it a small, simple, website maker.
Sketch Palettes - Sketch plugin to save and load colors into the color picker