green for on preview and red for live. This also means they can be CSS textual
colors (like “red”), although you can of course make the theme return only
“#ff0000” or similar if this makes your tally application simpler.
+
+Note that the tally endpoints have fully open `CORS <https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS>`_
+headers, so that they can be queried from anywhere; tally data is not sensitive,
+and this makes it significantly easier to query them from a web page.