My favorite one would be a combination of Dark and Blue.

I used Blue for some days but switched to Dark a few weeks ago. The Blue Theme is too light.

I tried using the dark theme but I could barely see the posts in my wall and the comments in articles (unless I highlighted them) , so I switched back to the standard theme.

This too

Also, I know this is kinda off-topic, but I wonder why I can't see the scores I give to the games in my collection (even with the standard theme).

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Yami no theme. (Dark theme). Thank you for adding it.

Dark looks smart, but needs tweaking. As already mentioned, areas like the articles pages and personal walls are difficult to read in dark mode, as well as some quoted posts. The hot topics as shown on the settings page are also difficult to read.

A slightly deeper green with increased contrast might make the buttons pop a bit more with the dark theme, but that's just my personal opinion.

Going back to standard theme now.

Default colors are the best for me. Bright, but not enough to make your eyes bleed. Golden middle, all I like.

I tried dark for a while. Went back to white. Had no idea there was a blue theme!

Should try it. It's like old times.

I definitely like the blue the best.  It's not exactly the same as the past, but it's a lot closer than the other options, and I did like the style from 10 years ago or whenever that was...

dark theme

Default, my eyes don't work well with dark themes.