The"new" colourful Tabs has nothing to do with the old one, which is shown in the screenshot. Actually it only colours the actual tab-and in the same coulour nearly the whole rest of the firfox header, exept the remaining tabs. The Top line colours change each time, you choose an other tab-which is more a nerve taking lightshow, because of the shrill colours, than helpful, as it was earlier! (and as it is shown falsely in the screenshot)