I have to say that when considering the historical verisimilitude of Beauty and the Beast, I'd be more concerned with the number of people successfully turned into talking candlesticks and let the rest roll. That said:

An 1807 census recorded 821 men and 461 women who were "black or of color" living in France outside Paris. Most of the non-white population, of course, would have been in the cosmopolitan capital city. Estimates from the late 18th century put the number of non-white people in Paris in the 4000 to 5000 range. Scholars have typically found this number a bit high but plausible. (Estimates for the population of color in contemporary London are 5000-10000, and London was around twice the size of Paris).

The gender imbalance of the 1807 village/town statistics is generally reflected in assessments of populations of color in ca. 1800 northwest Europe--a heavy male dominance. Many of the women, indeed, would have been biracial children of an African man and a French or English woman. Interracial marriage and miscegenation appear periodically as major concerns of the French, specifically government, and in intervening years, of individual judges.