Greenshot - Greenshot is a free and open source screenshot tool that allows annotation and highlighting using the built-in image editor.
Swatches - A fun and accurate color picker for the real world
ShareX - ShareX is a free and open source program that lets you capture or record any area of your screen...
ColorSnapper - The missing color picker for Mac.
LightShot - The fastest way to take a customizable screenshot.
Sketch Palettes - Sketch plugin to save and load colors into the color picker