Okay, decided to actually look into this myself

Apparantly red is the
first colour to go and has reduced dramatically by 10'. Which means that when the soldier fish go into the deeper areas of a coral reef to hunt they appear black/grey. So at night, amongst the coral, they probably do count as camouflaged.
Andym, looks like green filters out around 45'

Very nice paint job, the lighter streaks make me think of light flickering over it's surface