This is an area where I wouldn't mind a little splurge in design. These are supposed to be the greatest computing machines made, they should look fabulous and mysterious.

Well, a bunch of racks with green LEDs is more practical, cheap and functional, I guess.

Haha so green LEDs are cool again? I made a call back in 2004 that after blue LEDs became commonplace and white LEDs had their turn as the new hot thing, red would make a comeback. And it did. ;)

I imagine there have been multiple cycles through the spectrum since then…

Isn't that due to green being the highest energy of light for an LED available at that time? IIRC, everytime a new material was created to get the increase in band gap for a higher energy photon (i.e. blue or violet), there was a Nobel prize given out.

Tuning the band gap with a new material back then was difficult I think.

green has a lower band gap relative to blue/white, ~2V depending on chemistry, but there's something like that going on - IIRC human eyes are most sensitive to green around the ~500/550nm wavelength that green LEDs emit, so you can get good brightness out of low power.