Great question. Timing is everything. Generally, the "Colonies" had matured as far as they would by 1776 and boundaries had been mostly settled. So, that being said, the proper description would be "Colony of XXX, Village, Town, City XXX, County of XXX (beware of historic changes/combinations), British Colony of America."
The more important question is when to start using "United States of America." Is everything past 07/04/1776 the USA?
I've seen several lax mistakes in this regard, but I don't think it created any confusion. Using the correct form adds a degree of historical reality that I think is valuable to the interested reader.