[elvisds]

This was explained in demo website [1] that was submitted earlier today [2]

> It works by displaying a color whose brightness is way outside the standard range of sRGB color space.

> Unfortunately, this color cannot be represented with CSS colors (rgb(999,999,999) doesn’t work) or any of the widely-supported image formats. However, an HDR video can represent this color.

[1] https://notes.dt.in.th/HDRQRCode [2] https://news.ycombinator.com/item?id=36384625

[Jasper_]

In theory, you could do this with the rec2020 color space included in CSS Color 4. https://www.w3.org/TR/css-color-4/#predefined-display-p3

[jojobas]

Using any monitor in a room with a window on a sunny day you'll want to ramp up brightness way above the sRGB-mandated 80cd/sqm. True sRGB colours only make sense for print designers anyway, anybody else adjusts their white brightness as needed. This is a gimmick and Apple's usual pioneering stunt.