The part to note is "active" vs "usable."
PAR is the value that weights the amount of light a emitter outputs at all frequencies that can cause photosynthesis. While lumens are the light output period. PUR is the amount of light an organism needs at certain frequencies that will cause photosynthesis. This can be almost anything in the visible spectrum. Tomatoes like one frequency, or set of frequencies, while deep water corals symbiotic algae adapt to a much narrower bandwidth. Green plants are green because they absorb all frequencies but green. That gets reflected back to your eye. Corals work the same way. That's why hydroponic led
lights aren't green, they are the color opposite on the color wheel, magenta. That is the frequency of maximum absorption for a green plant. So the PUR of that plant would be in the magenta frequencies.
Of interest, green plants look black under magenta LEDs as I have in my algae scrubber, indicating little light is being reflected back but being absorbed in the plant tissues.