In the meantime, you can use the Dark Reader chrome extension if you're looking for a more extensive variety of dark mode for most websites. Install the Install Chrome Extensions add-on if you haven't already.
@pspstreet51 thank you SO MUCH for taking the time to answer my questions and for doing it in a very kind and informative manner. I'm of-course aware that it's taken a good amount of time for my inquiry to finally be answered, but I totally understand and can't even imagine how busy it probably gets.
Lastly please know that I truly appreciate everyone like you who volunteers their valuable time to offer their knowledge to try and help fellow users like myself. Thank you again and keep up the awesome work! God bless. - JR
@aadivishnu I would leave it up so that other users know about it and also for Opera developers -- perhaps they might fix the issue or put a note in the documentation about the effects of the battery saver option.
@leocg For comparison, I changed the search bar to Google. As you can see, this bug is observed only if Yandex ( Яндекс ) is selected in the search bar.google.png