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.
Since the office was established in 1789, 44 people have served as president. The first, George Washington, won a unanimous vote of the Electoral College. Grover Cleveland served two non-consecutive terms in office, and is counted as the nation's 22nd and 24th president. Thus the incumbent, Donald Trump, is the nation's 45th president. There are currently five living former presidents.