@azot In both light and dark theme, the active tab has a different color than inactive. However, Opera still has only two preset appearance settings to choose from. I appreciate the functionality of Opera, so I do not intend to change my browser. However, in this respect, the Vivaldi viewer has more settings - a lot of color settings of individual elements (creating your own theme in many respects) and even automatic switching between 2 themes based on the time. Opera could have similar settings, but no, not because it's hard to distinguish between active and inactive cards. Just because it has richer settings.