In simple terms, both blue and green light contribute equally to circadian interruption. The graph itself is a comparison of spectral power distributions among

In simple terms, both blue and green light contribute equally to circadian interruption. The graph itself is a comparison of spectral power distributions among several light sources. It's basically the signature of the light source, showing relatively how much of each color is produced in comparison to all the other visible wavelengths. The gray area is melanopic sensitivity. This is the light that the ipRGCs[0] in the eyes are sensitive to, which provide input to the circadian rhythm. The peak is approximately 480-490 nm, but the overall sensitivity covers both blue and green wavelengths. There's a great article on the blue/green concept by Ian Ashdown [1]. If you use the f.luxometer tool [2], developed by the f.lux team, you will see that same curve. EDIT (for clarity): In the graph you linked, ignore the color of the lines. That is just to distinguish the different light sources. Just pay attention to the intensity of the wavelengths on the x-axis. The y-axis scale is 0 to 1, as this graph is normalized, so hardly necessary to show. Let me know if I can help clarify this further! [0] ipRGCs: https://en.wikipedia.org/wiki/Intrinsically_photosensitive_retinal_ganglion_cells https://en.wikipedia.org/wiki/Intrinsically_photosensitive_r... [1] Melanopic Green: The Other Side of Blue: https://www.ies.org/fires/melanopic-green-the-other-side-of-blue/ https://www.ies.org/fires/melanopic-green-the-other-side-of-... [2] f.luxometer: https://fluxometer.com/rainbow/#!id=iPad%20Pro/6500K-iPad%20Pro https://fluxometer.com/rainbow/#!id=iPad%20Pro/6500K-iPad%20...