Most white LEDs are phosphor-based but hardy as bi-chromatic as you make
them sound. The little Cree in my pocket flashlight has the typical
broad peak around 450 nm and valley around 485 but it's quite continuous
down to 650, tailing off at about 670. Very different from the narrow,
discrete lines from a CCFL.
[Rich Webb]

Thanks, Rich.

I think the "striping" issue and potential variance between samples will make
for a less-than-satisfying result.

Thanks,
Dave