I have a situation in a video game where as the Netherlands I have a significant population count in modern day Indonesia that I could really use in mainland Netherlands.
I think I have read that soldiers were used but what about in industry and resource gathering? (any material will be good: India, Africa, Asia)
It definitely happened, but less frequently than you think - once colonial citizens see the metropole, they are exposed to the true inequality inherent in colonialism and begin to agitate for reform. The best example of this is the French experience in Algeria, where colonial citizens fought in WWI and II and filled in manufacturing jobs in mainland France, then returned to Algeria and began to agitate for reform.