According to Toller :

"Chris Lewis" wrote in message
...

I'm talking from the perspective of absolutely strict code compliance
from the perspective of an anal inspector:

Legally, you can't use a black or red wire as neutral, but you
can use white for hot (with suitable marking). You can't use
any of them as ground, nor can you use a bare ground for anything
else.

How exactly could using a red as a ground hurt anything?

I can't think of any compelling "bad scenarios" with sane individuals,
but there must have been a reason for NEC not permitting the marking of
a color normally used for hot as ground (or neutral).

It could simply be that they wanted _no_ exceptions whatsoever for
color codes, except that they decided that permitting the
"recolor" of a white wire as hot was essential for certain switch
circuits, and it'd cost the industry too much otherwise, whereas
needing to allow the reverse was too rare to worry about.

The worst case in this scenario might be that someone mucking
with the panel notices the red on the ground bus, thinks that
it is the cause of the whatever it was that made them look in
the panel (mutters "idiot!" under their breath), immediately jumps
to the conclusion it's the cause of their problem, and moves it
to a breaker.

That could have rather unpleasant consequences, the least being
that they've case-energized everything on that circuit.

There's a reason why I said "absolutely strict code compliance" which
such emphasis.
--
Chris Lewis,

Age and Treachery will Triumph over Youth and Skill
It's not just anyone who gets a Starship Cruiser class named after them.