I don't know that much shit, my educational and early professional background is in journalism, but then I 'jumped ship' (journalism at the turn of the millennium was a bloodbath and newrooms were all slashing 3/4 staff and keeping only the most experienced journos). I jumped to, well, ships, and studied to become a bridge officer but found better opportunities on smaller boats, where I could qualify as Master much sooner than cargo ships, and have more exciting jobs. My stock and trade became tourism (whale-watching), ferries, and oil spill cleanup operation command. I served my community by doing Search and Rescue w/ the CG Aux. Each of those was that rare type of job at sea where you actually slept in your own bed at night and got to watch your kids grow up. My last job I was hired for was on an Antarctic cruise ship (something I'd been working toward since the start, I'm fascinated by high-latitude locales) where the job was to create and give lectures while crossing Waddel sea, then transport/command shore parties, slaloming around icebergs with powerful 24ft Zodiacs and leading day expeditions ashore. This was my dream since I was a kid, and then a month before departure I got really sick, and ultimately hadda give it up, and the whole at-sea career because it was pretty serious but tough to diagnose. As Maxwell Smart used to say: "Missed it by that much!
Well, that was some tangent.... forgive me.
I merely figured it was Cree reds because they were the most popular at the time of my research and almost all "Full Spectrum" (a BS sales phrase BTW) fixtures had 690 reds on them. You see, Photone will want their one-algo-to-rule-them-all to be based, as close as possible, to the most popular "full spectrum" led setup. A bit of market research was all it took.
After that, I got my hands on a High Precision Spectroradiometer Integrating Sphere test analysis report from a commercial light that fit the description (a Kingbrite 1100w bar light - and ended up owning two of them; BTW, every manufacturer should be able to provide on on request). With that data, you can come up with a conversion algorithm because you get the output for each spectrum as a percentage of the total output. I have no science background, just learned how to do research in journo-school I guess.
.