In the "colors and styles" settings there are 6 pre-configured styles of various color combinations. I like how they are generally pretty subtle differences and you can customize them. The one big change is the dark setting. That is a drastic change for people who are not used to that. I like dark mode on many of my pages and websites but it is not for everyone. (BTW the WPForo dark style is GORGEOUS on my phone!)

I would not change this setting to dark for all my users, many would freak out and think their computer was hacked (I have an older demographic). But it would be nice if this was an option in the user profile settings for people to individually customize their experience. The dark style is really well done but it shouldn't be a 'one size fits all' option for a site.