Just Color Picker is a tool for capturing the colour of any pixel in any screen area and displaying its code in a variety of formats: HEX, RGB, HSB/HSV, HSL, ...
A system-wide color picking utility for Windows to pick colors from any screen and copy it to the clipboard in a configurable format. Getting started · Using the Color Picker editor
By default, you'll use Windows+Shift+C to activate the color picker. You can change this keyboard shortcut to your preferred one from this screen, if you like.