Did Opera just update to change the colour of the sidebar, as well as make the start page smaller?
I don't usually like dark mode on things, but I did prefer the darker sidebar by far. This white one clashes with a lot of other webpages in kind of an annoying way and it's really distracting. On darker webpages it's really jarring. I feel like the browser isn't properly lined up with my screen.
I know I can hide the sidebar or turn on dark mode, but I like having it there, when the colour isn't messing with my head at least. I also find the little opera menu that replaces the sidebar when you hide it gets in the way much more. It takes up space from tabs and looks too much like one. It gets tiring when I accidentally click on it when trying to get to my first tab. Additionally, when it comes to using opera in dark mode, I personally just don't like how dark mode looks. Most of the time I spend on the internet is on youtube, in a darker theme, and I find it's easier when the search and bookmarks bar are lighter since it makes a nice disconnect from the site - it just feels a lot more organised than in dark mode where everything tends to blend together. Not to mention, it feels really silly to have to make my opera experience worse by turning on dark mode, when it was perfectly fine before.