in france the apologists for colonialism constitute an important part of the rightwing of their political spectrum. i am not sure how that plays out in other former colonial powers. i suspect it is similar, but don't know.
in reversal, even during the colonial period, there were lots of anti-colonialist, like sartre say, who opposed the ideologies of colonialism.
we would have expected the left, led by the communists, to be systematically anticolonial, but stalin was too realpolitik for that. when the socialists came to power in france in the 30s, and continued the colonialist ideology, stalin backed away from supporting
national liberation parties or even movement for rights of indigenous people to vote. it was on that issue that camus quit the communist party in algeria, having been betrayed by the soviet two-faced turnabout.