Postcolonial migration to metropoles made race visibly domestic by the late 1960s

Evidence

Empire, however conceived, had struck back not just in the assertion of nominal independence but in increasingly large numbers of now excolonials showing up at the metropolitan door. Extension and renewal of economic, political, and cultural dominance conjured a different set of engagements. Race could no longer be seen simply as the “out there.” By the late 1960s, visible heterogeneity was becoming remarked in Europe and finally undeniable in settler societies such as the US, Canada, and Australia, just as civil equality was being insisted upon. — David Theo Goldberg, The Threat of Race, 1777