On Sunday, November 13, 2016 at 8:11:28 AM UTC-8, Leon wrote:

Fast forward and LED's lights now use, in many cases, yellow filters to
filter out the blue.

Actually, that yellow color is a phosphor; LED illumination starts with a blue
LED (sharp spectrum line) and generates other wavelengths with phosphors.
Fluorescents start with ultraviolet (from mercury in the gas of the tube) and
generate visible light with phosphors.