The core constraint is the ability of any particular monitor to product light at these wavelengths. In simple terms, LCD panels often shine a white backlight th

The core constraint is the ability of any particular monitor to product light at these wavelengths. In simple terms, LCD panels often shine a white backlight through a panel with separate red, green, and blue filters for every pixel. A fully-white image, then, should have the broadest spectrum possible for a specific screen. Apply a pure red image, e.g. 0xFF0000, will selectively filter the spectrum to mostly eliminate the green and blue wavelengths, but depending on the filtering material may also eliminate longer wavelengths too. Edited to add: This graphic [1] illustrates the spectrum produced by common light sources. Old LCD panels used fluorescent backlights like the bottom example. More recent LCD panels often use an array of LED backlights. The bottom line is that, if you're trying to maximize red light exposure, you're much better off with: sunlight >> incandescent bulb light > a very "warm" LED light. [1] https://www.waveformlighting.com/img/full-spectrum-graphic.png https://www.waveformlighting.com/img/full-spectrum-graphic.p...