> > I've dones this before myself when I boot up into a regular
> > kernel under 8 bit rather than one of my experimental ones.
> 
> So, this souldn't have happened... hmm.

It *has* happened in the past but I don't remember the circumstances.
In any case, if you somehow start X in 8 bit under a kernel without
color support everything comes up in shades of yellow. Apparently because
this is the part of the palette X is supposed to use for black.