Brazil certainly has seen a massive change.

A 2015 autosomal genetic study, which also analyzed data of 25 studies of 38 different Brazilian populations concluded that: European ancestry accounts for 62% of the heritage of the population, followed by the African (21%) and the Native American (17%). The European contribution is highest in Southern Brazil (77%), the African highest in Northeast Brazil (27%) and the Native American is the highest in Northern Brazil (32%).

Argentina too

Many genetic studies have shown that Argentina's genetic footprint is primarily, but not overwhelmingly, European. In a genetic study involving 441 Argentines from across the North East, North West, Southern, and Central provinces (especially the urban conglomeration of Buenos Aires) of the country, it was observed that 65% of the Argentine population was of European descent, followed by 31% of indigenous descent, and 4% of African descent.

Another example would be Canada, but that's a bit on the nose.