I have read that Paraguay has the highest percentage of Europeans in S. America.
No.
Lowest maybe.
Perhaps you are thinking of Uruguay?
You state, “I have read that Paraguay has the highest percentage of Europeans in S. America.” That is not the case as the European-Guarani Indian mix predominates in much of the country. Blacks are hated in Paraguay because in the 1860s War of the Triple Alliance (Brazil-Argentina-Uruguay vs. Paraguay) Paraguay’s enemies used blacks front and center in a war that truly decimated Paraguay’s male population. The only blacks to be found in Paraguay are in the east in the Parana river region where they are settlers on recent land clearing operations.