Unfortunately, the new version 66 of Firefox interface is worse than before. My tabs have the same colour than my Windows background colour (blend in and disappear), and my bookmark folders which I keep at the top underneath the task/search bar are WHITE! again, difficult to see as they blend into the white of the task bar. I do hope that this is not permanent and intentional as that's a VERY POOR design. I can't find anywhere the option to customise these colours. Please advise where / how can I CHANGE these colours to make my tabs and bookmark folders stand out. thanks.