Hi,
On Opera Touch on Android, I love using dark mode, as it saves my eyes in the dark, and saves a little battery on an OLED screen to.
One thing I've noticed though, is that when opening some links, a default blank white page appears on screen just before the page loads.
When browsing in the dark this means that my eyes get blasted with a load of bright light all of a sudden. To counter this I find myself pointing the phone display away from me in the dark, just in case the whole screen lights up suddenly 
It's not a big problem by any stretch, but it also seems like one that would, at least in my naive mind, be relatively easy to fix.
If, when in dark mode, a page could default to a dark background, rather than white, until the page has loaded, then that would avoid the issue.
I can reliably reproduce it just by clicking the 3 dot menu and then clicking help - as the page starts to load it lights the whole screen up white.
I hope the feedback is helpful, and I also hope you'll consider this tweak - It would help me, and for other people who browse in the dark I imagine they would appreciate it too 
Thank you.