As far as immigration from the colonies to Metropolitan Portugal, I am not aware that there were any restrictions. I think throughout the 1950s and 1960s Portuguese government never even considered poor Africans immigrating en masse to Portugal. Mostly because Portugal had such a large pool of unskilled labour.
However, in by the 1960s there were Cape Verdeans moving to Metropolitan Portugal. By 1973 there were an estimated 20,000 Cape Verdeans living in Metropolitan Portugal (mostly men) working in construction, industry, mines etc in the greater Lisbon area. Many were temporary labourers.
Between 1963 and 1974 104,767 Cape Verdeans worked in Metropolitan Portugal at one point or another. The government created in January of 1973 the "Centro de Apoio aos Trabalhadores Ultramarinos" (Support Centre for Overseas Workers). This agency was setup to give them assistance with housing, healthcare, jobs etc.