More colors for "set color" feature + assign tab background to domain

[Naezr]

In the tab context menu we have the "set color" function. It allows you to paint the tab background in one of the presented colors. I haven't found any way to adjust these colors or add my own. It would also be quite convenient to assign a color to a certain domain. Yes, there is already a function to color tabs based on domain, but the colors there are kind of weird. And this function colors all tabs at once. I want to assign my own, manually selected colors to a few specific domains. For example, I want the background of all youtube.com tabs to be red, but the other tabs to have a standard background.