Under dark skies I can see the green colour from M42 with the naked eye, and even more so in binoculars. That's probably the best bet to see any colour in nebulae.
I can't see it from here in town - but if I am camping out in the national park where there are no lights for a few hundred km then this colour is visible.
Bird
-------------------- Deep Sky Optics 13.1" f/5.5 newtonian,
PGR Dragonfly Express, PGR Dragonfly 2
RedHat Linux + Coriander http://www.acquerra.com.au/astro/