I've realised that when we added a few different themes a while back, a lot of the conversation on it was not public and any that was is now ancient history.
So, we have 2 main themes, with a couple variations. The default one that you are probably looking at is largely light grey with red detailing, this is the 'light' theme. There is a very basic adaptation of this called 'SFW'. i.e. Safe For Work. Then we have the old default 'black'. If you signed up to the forum some time ago, missed any of the changes in themes and have never looked at them, chances are that this is your current default. The 'light' theme is far more mobile friendly imo. Finally, there's a slight adaptation of that one- 'red'.
It's worth bearing in mind that when applying colour to text in posts, some colours will be terrible to read on one or other of the different themes. It's for ease that I generally stick to default text colour with my event posts these days, I CBA to think about what it will look like on the black
Changing it is simple. Go to profile, edit profile and settings. Scroll down and you'll see the option.
Agghh so bright lol. I've been using the original theme. I guess the theme most people use will be the one to go with, which I'm guessing is this lighter theme. It does look good I must admit, it'll be new for autumn (or fall in USA)
As the one who requested the SFW theme I'm perfectly OK with removing it as the light is also SFW imo and what I use while at work. At least that gets rid of a theme that is almost identical to this one and simplifies our forum, even if it is just marginally.