In 1951, Archbishop Fulton Sheen as the National Director of the Society of the Propagation of the Faith proposed the Mission Rosary to promote unity and world peace. Sheen believed that we needed to pray not just for ourselves but for the whole world, especially the poor and vulnerable at home and throughout the world.
Each decade of the Rosary is in a different color, denoting five regions of the earth (as Oceania or "the Pacific Islands" are not quite a continent and the Americas are two continents). The idea is that the faithful could reflect and pray for these regions as they reflect on the Holy Mysteries of the Rosary.
Archbishop Sheen invited the People of God to spiritually take a tour of the world as they prayed the Rosary making a spiritual work of mercy by helping the Holy Father in evangelizing the world.