I have not found a designation for "Creole" in the 1850 or 1860 census. It wasn't a term that was used as often as it is now. You will find the designation "black" and "mulatto" in the records. I am assuming if the census taker looked at the color of the person's skin they made the judgement (there are family members that were designated as "mulatto" who were darker than me and I am not "fair skinned"). Check out my tree- there are several members in my tree who were free people of color and received had designation- surnames include Lavalais/Lavallais. The Parish catholic churches also kept excellent records- although I cannot find a racial designation, I found my family members were married, baptized and buried in the same church for the most part.