Green or white seems to be the standard for submersible lights. I've only fished over green lights once, & only for a few hours, but I've fished over white lights since I was a kid. I've used Coleman gas lanterns, floating headlights, and submersibles ... and really can't tell you which lights ... above the water lights - on the surface lights - or submerged lights ... are more productive, because they were used under very different circumstances.

Personally, I don't think you could go wrong with either color ... but, unless you're fishing heavily stained water, I see no use in putting out mega-power lighting, since most of the time any light in the area will draw schools of baitfish and quite often the fish will stay just outside of the main area of lighted water.