When to turn on moonlights?

[PoonTang]

I remember reading somewhere that if your moonlights are blue or white then DO NOT leave them on all night. Red lights are OK. Cant remember exactly why but it had something to do with the nocturnal critters in our tanks. I know when i have mine on i dont see any pods or worms. But if i turn them on when the tank has been dark for a little while you will see all the little critters scatter for cover.