Thanks again and all you extension writers, make a ColorfulTabs like extension.Mozilla Firefox suddenly doesn't open any web pages, or it displays a black (blank) page in any website you try to open. Oh well, all of this belongs in a different section of this forum. I often have 3-4 windows with a total of 35-40 tabs opened. Customizing Firefox is its strength and I think I have so many extensions loaded and then keep too many windows open with tons of tabs which causes problems. I'm trying out Opera since I am tired of the crashing and slowness of Firefox and tired of the simplicity of Safari meaning there are many things that can't be done with it. Being able to customize windows like you can in Windows has always been a major lacking in the macOS. I especially like the current macOS ability to have side by side windows with two separate applications side by side each one being active at the same time. I have the luxury of a 27" monitor and real estate isn't a problem. I suppose they are trying to minimize the extraneous parts of a window giving more real estate to the actual website. Somehow on a Mac, Opera manages to put the tabs on the window's primary bar replacing the URL and doesn’t make it its own toolbar. It's too bad the various platforms for Opera are not in sync.