Question

What contributed to changing european views of asians and africans in the nineteenth century?

Answer 1

The industrial revolution did.

In the beginning, the only perceived difference was  that they were not Christians so they wanted to baptize them. After the industrial revolution, the European countries developed rapidly while African and Asian countries didn't and Europeans believed that this was due to their superior race so they decided to colonize them under the pretense that they would help them develop.