That's why I don't like coloured hoses or wraps, or coloured reg face plates.
It does interfere for about 5 minutes when teaching students that just watched the Padi video with those items in full display, but the confusion is short lived, and these adults had no difficulty understanding a simple concept.
We use 5 and 7ft hoses for OW diving as it makes ascending face to face easier, unless we're trying to gang-rape each other and get in the way of our team-mate.
Have to admit though, the only time I've had to deploy the primary for 'real' is when a solo diver on the same boat invaded our team and was too low to continue, so it was either watch him CESA or drown, or allow him some gas. We were happy to have him a few feet further away than a standard length hose permits.