I've found the results are better using multiple light sources- of a lower intensity- than trying to light the whole area with one super bright light. Or, if youve got one bright source, dont have it near the camera. The reason being if someone gets close to the camera a bright light can cause over exposure of their face- making identifying them impossible. Ive got one mains powered sensor light turned off for that reason (it's right next to a camera.)
I haven't actually tried the Colorvu with just the onboard light, but I am using their lights (at a low intensity) for fill lighting closer to the cameras. My street lighting is next to useless so I already had a variety of LED lights installed- some on all night, others motion activated. (I was previously using older 3MP "powered by Dark Fighter" IR cams in colour mode.)