Command for detecting whether the system is using a dark or light desktop theme?

There's [a way in browsers](https://developer.mozilla.org/en-US/docs/Web/CSS/@media/prefers-color-scheme) to query if the user prefers a dark or light theme so that a website developer could adapt the website's colours according to user preference. Is there also a way to detect that on the command line? Is there a command that outputs light or dark (or some equivalent boolean-valued output indicating light or dark?)