Did you change something? Or discourse broke all by himself?
If new colors for the light theme are desired, it would be better to create a new one instead of changing the default one as these new colors are not nice to see, i.e., makes it hard to read stuff.
I use the dark theme, all the colors are changes.
I also have a Dismiss Button in my notification list.
so I think this might be intentional (?)
however, I liked the other dark theme better.
but I don’t think I had the dismiss button, which is nice to have. (I also remember a user asking for something like this)