DOM Element Background Color Selector — AtlanticSwan

After clicking on the icon for this addon, it will alert to you the background color of the next in page element you clicked on. If that element has no background color, it will go to it's parent, then the parent's parent, and so on until either the entire thing is transparent or it finds a color.

It will bring up a window confirmation telling you the color in hex, and asking you whether you'd like to visit a seperate page to see the color in full (solidcolor.netlify.app (also mine)).