For example, you want to dynamically generate a background and text color based on a hue. With hsluv you can simple do `hsluv(120, 60%, 10%)` for background color and `hsluv(120, 60%, 90%)` for foreground text color, you will have text on background with 80% perceived luminance difference, you can replace the `120` in my example with whatever hue in the `0-360` range and have consistent results.

The idea is that the color space is linear (perceived) with saturation and luminance regardless of hue.

You can see it clearly if you compare something like http://www.hslpicker.com with http://www.hsluv.org/ if you drag the hue slider on the hsl version, the luminosity varies, it does not on the hsluv version.