Final answer:
The statement that the highlands of Uruguay look purple is false. While certain geological and biological conditions can cause purplish hues to appear in landscapes and bodies of water respectively, this is not a characteristic trait of the Uruguayan highlands.
Step-by-step explanation:
The assertion that the highlands of Uruguay look purple is false. The geography of Uruguay does include highlands but they are not known specifically for a purple hue. The description of the highlands looking purple may arise from artistic interpretations or specific time-of-day observations where shadows or certain light conditions might give a purplish tint to landscapes.
Moreover, geological formations, like the Silurian and Devonian sedimentary rocks mentioned, can exhibit blue and purple colors, but this does not mean that the entire highland region appears purple in color. Similarly, certain biological factors - such as high density of specific algae - can cause water bodies to appear purple as seen in examples like the Great Salt Lake in Utah but such phenomena are not characteristic of Uruguayan highlands.
Uruguay is highly urbanized with many cities and urban centers that attract tourism. Its capital, Montevideo, is a vibrant and cosmopolitan city with high-rise apartments and commercial buildings. While Uruguay has a diverse and rich landscape, including agricultural lands and coastal areas that are indeed attractive to tourists and locals, the highlands themselves do not inherently appear purple.