I would find compact fluorescent bulbs that have a color temperature near that of daylight (not necessarily "daylight" bulbs). You want a bulb with a color temperature of somewhere between 5,000 and 6,000 K. These numbers are usually on the back of the bulb's packaging somewhere.

Compact fluorescents are better than other bulbs because you get a lot of light without a lot of heat (which is a problem with herps).

Also, make sure your boxes are pure white, not some off white color which would affect the visible color.
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Chris Harrison
San Antonio, Texas