I gave it five stars although it doesn't work right now in FF57, as a token of my appreciation for previous versions of Colorful Tabs. My criticism is aimed at Mozilla for not being cooperative in allowing this add-on to work properly in their latest version. Colorful Tabs isn't merely a pretty addition to the FF interface, it's an essential accessibility enhancement tool for people suffering from various forms of visual impairment, as well as a productivity tool. For the life of me, I can't imagine why Mozilla would choose to ignore the impact and benefits of this wonderful add-on. I'm really tempted to switch over to Chrome over this issue.