I have a CFL fixture that is running 2 28w 13" lamps.
They come in 6700k, 10000k, 20000k, and 50/50 lamps. I used it on my sump for my saltwater fish tank refugium.... hoping to convert it to chameleon lighting.
My question is what's the best choice for the chameleon and plants?
5.4K to 6.8k is what you should use.
That is the Kelvin color temp of natural sun-light.
Anything with a higher kelvin is producing light that is above what natural day light is.
You see, water (salt water) naturally filters out red and then yellow and lower wavelengths, (hence the ocean appears blue)
So "white-er" to "blue-er" light (8k-20k) is natural to light a reef environment that would be 10 - 80 feet under water. ie: the blue shift.
However, that would NOT be natural or correct lighting to use in lighting a terrestrial environment.
Also, you will need a different light fixture to house a UV producing bulb, because as of right now, there are no good UV reptile lamps in PC design available in the US. (I have been thinking about importing some... but the demand just hasn't been there.)
Because the correct UV is the most critical thing.
Then second is proper "brightness" and color temp and spectrum.
Hope this helps.
Cheers!
Todd