https://forums.opera.com/topic/21007/theme-and-layout-of-the-opera-browser-45-0-2552-812/3?lang=en-US
Theme and layout of the Opera browser - 45.0.2552.812 | Opera forums
Jun 13, 2017 - Do you have this problem? There are also some difficulties to see inactive tabs too.
theme and layoutopera browser