Hopefully this is the right place to share this and isn't a repeat of a post made earlier.
I just posted for one of my stories and I semi-randomly picked some font colours to highlight dialogue. Two of the colours I chose were navy and beige. I noticed after I sent in my post that the text wasn't showing up at all - there were gaps that looked like I'd deleted my dialogue by mistake. I went back to modify it and noticed that the dialogue was still there, it just wasn't showing up because of the font colours. I changed the colours and now it's fine.
I only noticed two that weren't working correctly but I haven't tried out most of the other colours. I'm not sure if this is likely to be something that's affecting the whole site, but I'm guessing it might be.