Sure, but I don't see them mention what they're actually using for LEDs at all. They mention a "colour fidelity index" but I'd expect a manufacturer part number or something so I can pull the datasheet.

Funny enough, the best evidence for this study is that they should probably move somewhere with more sunlight if they can't spell "color" right... /s

They are not using an index much, they are showing you actual spectral graphs. Ask an AI to understand how that is the actual info you'd want.