Why don't they make the red LED lightbulbs using gallium arsenide phosphide (GaAsP)?

I've opened up the package of a walmart red LED party light, and it's a ring of white (about 5000k color temperature) LEDs on a PCB underneath a red plastic dome that absorb most of the light and heats up! Why not just use a semiconductor that already emits a clean red, and that doesn't need to be... show more I've opened up the package of a walmart red LED party light, and it's a ring of white (about 5000k color temperature) LEDs on a PCB underneath a red plastic dome that absorb most of the light and heats up! Why not just use a semiconductor that already emits a clean red, and that doesn't need to be filtered? Odds are, it's marginally cheaper to use white. I first ran into this when the LED brake lights came out, they were a rich red, now all I see are the white brake lights, and I'm kicking myself for not getting the really red ones when I had the chance.
So the question remains; why can't I find a red LED light made out of real gallium arsenide phosphide (GaAsP) red LEDs? An acceptable answer would be that to get the same light output it would have to be the size of a basketball and it would cost $175.00!
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