i wonder what genre hawkeye wanted to use the sepia for....cough cough
A documentary on cuttlefish?
I actually had that same question in mind, regarding sepia allowance and other shades.
I'm not sure if the term is the same, but many B/W films used coloured shades of celluloid to change a mood when sound and dialogue was not available. Even then, colour was actually important.
An old copy of "Phantom of the Opera" that I have (with Lon Chaney Sr, 1925), is totally B/W for the duration, aside from his appearance at the Masquerade where the shading abruptly turns blood-red.
Right now I am watching a B/W film (The Cabinet of Dr Caligari, 1919) that has used colour (blues, yellows, reds) in every single scene so far... as was originally done! I know, it sounds nuts.
Dying the film was pretty effective, I guess.
______
Anyways, good of Poke to settle the question. I ca get to work on newer idea now.