hmmm ..he ponders white light
realization of RGB-LED white lighting has many challenges
A requirement in white light applications is that lamps of the same type have the same color point.The color point may change with time or temperature,but lamps sharing the same history must all change in the same way.For example,it is unacceptable if all fluorescent lamps in a office are not the same color.it is also unacceptable if a LCD monitor displays a different white color point
at different points on the screen.
LED characteristics are far less reproducible than conventional lamps.
LED's vary in lumen output and wavelenght,and in their dependence
on temperature and time.Since mixing one or more red,green and blue LED's is creating white light,varition in one color(or one led)
can have a significant effect on the color point.In addition uniform
spatial mixing of the light from a small number of high power LED's is difficult to achieve.Great care be taken to ensure that color uniformity over the spatial light distribution from the LED lamp is at acceptable levels.
So the white light can be made from RGB, duplication will not be easy.