Probably depends on the colonialist. I expect many were in it for money at the expense of the colonised population, but I expect just as many did it to "civilize and raise up the barbarians as good christians".
Do you have any examples for this ?
eg: Daisy Bates oozed good intentions
https://adb.anu.edu.au/biography/bates-daisy-may-83
https://en.wikipedia.org/wiki/Daisy_Bates_(author)
and strongly put the case that:
"As to the half-castes, however early they may be taken and trained, with very few exceptions, the only good half-caste is a dead one."
But yeah, good intentions.