The advantage of OKLCH is not that it produces better colors, it's that you can vary a color reliably. They sold HSL to us as a way to vary the hue easily in a

The advantage of OKLCH is not that it produces better colors, it's that you can vary a color reliably. They sold HSL to us as a way to vary the hue easily in a way that's not possible with #000000 without manually computing it first. The reality is that the hue parameter in HSL also considerably changes the luminosity of the color. The tool you linked only demonstrates that OKLCH can also display colors that rgb() can't, but most of them are the same.