@leocg Thank you for your feedback.
I am sorry that I did not scan trhough the Froum good enough. I simply did not know that.
The behaviour was also not consistent as some Opera tabs are not red and one is and this changed.
But thanks to your note - I found the interrupted download that I did not need anyhow and removed it. At this moment no red colour. So thank you very much.

Hello All. The Opera Tab in the Taskbar is displayed with red background. I want to understand when and why?
I do not wish any signal color in my Taskbar. How can I change that?!