https://forums.opera.com/topic/23099/issues-with-autoupdating-and-os-compatibility/3

I found a way to disable the auto-update feature in the MacOS version of Opera.
If you wish to do so follow these steps:
1] Go to the Applications folder and click on the Opera.app while simultaneously pressing the "Control" key you will get a pop up menu. From that menu, select "Show Package Contents" which should be your second option.
2] Then a window opens with a folder that says "Contents." Open that and then you will see a bunch of files and folders.
3] Open the folder that is labeled "MacOS." Inside you should find a set of "exec" files. There is one called "opera_autoupdate"
4] Rename that to "opera_autoopdate," (just one letter wrong so you can change it back if so needed) and then closed everything and launched Opera as usual.
When I opened the opera://about page the app said it was checking for updates for about 5 minutes then displayed "An error occurred while checking for updates."
The app behaves normally in every other way.
So apparently I accidentally found the way to disable updates on the MacOS version of Opera. I was just fooling around and didn't think it would work, but it does.

Further to my previous comments, I'm afraid, after many years as an Opera lover, I've now moved over to Vivaldi. Endlessly customisable and, LOL, made it look like the older Opera in Dark mode. Plus it has Side Notes built in and didn't have to find an Extension.

Repeating myself, the View 'Extensions Panel' (Not to be confused with the 'Side Panel'), is a total mismatch to the rest of the theme, Windows or Mac and looks unfinished.

Should Opera go back to the older theme prior to v60, I'll look at returning.

if your on windows another one you can look at is the cent browser. it truly is as feature rich as vivaldi. if i were still running windows i'd have it as by backup browser instead of chrome, yes that means in linux opera is last after vivaldi vivaldi-snapshot chrome.

Repeating myself, the View 'Extensions Panel' (Not to be confused with the 'Side Panel'), is a total mismatch to the rest of the theme, Windows or Mac and looks unfinished.

Should Opera go back to the older theme prior to v60, I'll look at returning.

Totally agree. In addition, the previous version (V58) had a dark sidebar with tabs being light gray. New version- both are either all dark or that horrendous baby blue "light" theme color.
Time machine let me go back to V58 and I may never close Opera again if they don't allow a bit more customization.
I will also move to another browser if this is not addressed.

try dark reader in vivaldi or cent, either browser puts opera to shame.

In Windows, the Extensions bar is still the old dark grey and a total mismatch to the rest of the blue/grey and on a Mac, the Extensions bar is non coloured, with any Extension Icons being the same colour and the result is you can't see your Extensions, unless you vaguely click over them.

It looks to me, as though the Theme is not complete, apart from the fact that it's horrible anyway, LOL.

Blue? I don't have that issue on Windows. However the dark mode still has it's issues. It's OK at normal to high brightness under proper lighting, but take it into the dark with low brightness and it's really hard to see what tab is active :|

exactly. I am making exploration about some topics and after a while number of tabs reaches dozens. And ı can't see which one is my active tab. you should increase the contrast. Please. My using exprerince speed of Opera yield suddenly decreased.

And also ctrl+tab pop-up size is gigantic. The wrong tab opens accidentally when Mouse cursor over [ctrl+tab]pop-up window.

https://chrome.google.com/webstore/detail/dark-reader/eimadpbcbfnmbkopoojfekhnkhdbieeh

Yes. Blue-Gray. This is pretty clear to see.

When you dont have that issue on your windows you either dont use version 60, dont use the dark mode or your monitor is extremely bad calibrated.

It's OK at normal to high brightness under proper lighting, but take it into the dark with low brightness and it's really hard to see what tab is active

+1
A dot or similar would be nice.

Besides other errors and bugs (Like Dark - almost entirely black - entry box auto complete suggestions) this is something i cannot understand why opera did this. it makes no sense at all. it looks ... well not good and pops out on the screen like a graphical glitch.
The old dark mode color scheme was simply perfect. but this? no way...

I can't believe that I'm now on the search for an alternative browser just because an dark mode is so bad implemented.