Poland is 16% larger than Colorado (USA).
Area: 312,685 km2 World Factbook
Population: 38,346,279 (July 2014) World Factbook
Poland, officially the Republic of Poland, is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine and Belarus to the east; and the Baltic Sea, Kaliningrad Oblast and Lithuania to the north. Wikipedia
Colorado is a U.S. state encompassing most of the Southern Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains. Colorado is part of the Western United States, the Southwestern United States, and the Mountain States. Wikipedia