TIL that Firefox has a built-in eye dropper tool. Neat, so I don't need a separate extension for this anymore.

Main Menu -> More Tools -> Eye Dropper

@haeckerfelix oh, thanks for the shortcut! I knew it existed but I thought you could only activate it via Inspect.
@jvnknvlgl @haeckerfelix you can do it from the search bar too. Search for pick a color or color picker and it will show up.