IS that not just to let you be aware of which tab you are on. ? I get a colour change in hover over on a default scheme on a New Tab . As well Tabs not being used but are open have different colour than the one I am on. Maybe this is just to help keep track since using such a dark scheme. Might want to explore these : https://www.google.ca/search?q=firefox+compact+dark+theme+help&ie=utf-8&oe=utf-8&gws_rd=cr&ei=fwRrWfy5M4HejwOaoITIAQ

Please let us know if this solved your issue or if need further assistance.

Pkshadow said

IS that not just to let you be aware of which tab you are on. ? I get a colour change in hover over on a default scheme on a New Tab . As well Tabs not being used but are open have different colour than the one I am on. Maybe this is just to help keep track since using such a dark scheme. Might want to explore these : https://www.google.ca/search?q=firefox+compact+dark+theme+help&ie=utf-8&oe=utf-8&gws_rd=cr&ei=fwRrWfy5M4HejwOaoITIAQ Please let us know if this solved your issue or if need further assistance.

no I'm talking about this, the tab lighting up is normal but the curved lines marked in red (in the picture) is what I'm talking about

Are you using another full theme that still might have effect?

• "3-bar" menu button or Tools -> Add-ons -> Appearance

Tab related extensions like Tab Mix Plus might also try to override the CSS rules applied like the compact dark theme.

Do you have any code in a userChrome.css file in the chrome folder in the profile folder?

• http://kb.mozillazine.org/userChrome.css

OK, after trying various different things like installing classic theme restorer and such, nothing worked. So i decided to reinstall Firefox and it worked, the rounded tabs have disappeared. It was probably a problem with multiple themes working together (i.e default + compact dark).