If you have the older Aqua Vu micro, I found mine automatically switches on the IR lights and to B/W for higher contrast. The lights will switch off automatically in better natural light condition and the color returns.
The new Aqua Vu micro AV with DVR has the on/off for the IR bulbs. On its maiden trial the new camera frozed up after 5 hours in the water
Traded it in today, and maybe try the model again this weekend. The resolution and picture quality is noticeably better in the new generation, plus video out option or DVR.