Just Color Picker - Free portable colour picker and colour editor for web designers, photographers, graphic designers and digital artists. Supports Windows and macOS.
ColorMania - Colormania is an advanced color picker utility, especially created
Developer Color Picker - A custom color picker designed specifically for developers.
Paletter - Easiest way to create professional color palettes
Lumu Power - Turn your iPhone into a professional color and light meter.
gpick - A color picker and color scheme creation tool.