The Federal census of 1860 will not use the word "Creole". David's reference to "free men of color" in the Baton Rouge newspaper fits with his earlier references to how men of mixed race origins were treated under state law. For example, in Mississippi slaves manumitted after a specific date (usually 1831) were not allowed to remain inside the state. Those born earlier were given special status as citizens and frequently termed Creole.
I'm more familiar with Alabama and references to Creoles living in Mobile and along the Gulf Coast. These were often descendants of early Spanish and French settlers who had intermarried among the Indians and sometimes among free blacks or slaves.
If you have specific references to antebellum Louisiana state law on this subject, please post.