Were they also cruel, like any other colonialists, or lenient? What were the socio-economic programs that were implemented to the natives? Was it bad, or just ok?
Is there a time and space you are most interested in? The French Empire was global in nature and exercised overseas control of territory from 1536 to the present. That is to say, there is a lot of variety so narrowing it down a bit might help find you the answer you are looking for!
Louis Ferdinand Celine's novel Journey to the end of the night provides a description of life in the french African colonies at the turn of the 19th century. Though it is not a historical analysis it does give some insight, and the book itself is a masterpiece (despite controversy around the author himself).