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.
The head of state of the USA has been a president since 1789. In that year, George Washington was elected and inaugurated as president of the United States of America. He was inaugurated for the first time on April 30, 1789, and for the second time on March 4, 1793.