From the middle of the 19th century, there was a myth in the western world about being a "superior race". For example in France Jules Ferry [0] said "it is a right for the superior races, because they have a duty. They have the duty to civilize the inferior races."
It went much further than skin color differences, my own ancestors in the Western part of France, were called "animals like people" by Parisian politicians during the 19th century.
For those who admire Victor Hugo (a French writer of 19th century), he wrote a lot about Africa and their inhabitants (and also of inhabitants of Brittany and Vendée). His views on "inferior people" are absolutely terrifying:
"In the nineteenth century, the white man made true men of black people ; in the twentieth century, Europe will make a world of Africa."
It went much further than skin color differences, my own ancestors in the Western part of France, were called "animals like people" by Parisian politicians during the 19th century.
[0] https://en.wikipedia.org/wiki/Jules_Ferry#Colonial_expansion