[davidkunz]

I got confused because I thought it would set a background color. For text it's inverted and hence correct.

[erhaetherth]

It sets the foreground/text color because it's used with the `color` property (https://developer.mozilla.org/en-US/docs/Web/CSS/color). You can use it to set the background color too in which case you'd do `background-color: light-dark(white, black);`