> They now all look the same, but for some reason they look almost
> white, not black.
> 
> I cannot reproduce this on systems to which I have access, so you or
> someone else will have to debug this with that particular terminal.

Fair enough, if someone else has the issue they will be able to find
this hopefully

> What does the below report on that terminal?
> 
>  M-: (tty-color-desc "#000000000000") RET

("#000000000000" 0 0 0 0)


> What do you mean by "dark theme"?  This is in "emacs -Q", right?
> without any theme being loaded by Emacs, right?
It wasn’t emacs -Q, but emacs -Q is even worse (nothing visible for the
first lines)