Before extrusion, the HDPE can be pigmented to yield color-coded pipe. Common PEX tubing colors are natural (hazy clear, unpigmented), white, black, red and blue. The red and blue colors are used to help plumbers and homeowners distinguish between hot and cold water supply lines.
No, there has never been a US President from an independent party; however, at the time of his presidency, George Washington was not affiliated with a political party at all, as there were no parties in the brand new United States of America.
William McKinley, Jr. (January 29, 1843 - September 14, 1901) was the 25th President of the United States, and the last veteran of the American Civil War to be elected to that office. He was the last president to serve in the 19th century and the first to serve in the 20th.