You can add the custom edition, page and text attributes to schema, and access them in GNML tags. Since the version 2.0, we added to the schema two standard attributes prefixed by the Bell sign @, e.g.:
>co !@pg_sectionColor!<
>co !@tx_sectionColor!<
This is covered by the change GN4-1834.
pg colors work only on master pages. tx colors work only in article elements.
See Section-level color attributes for text and Section-level color attributes for master pages.
See also