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.
JFK was the first former scout to be President. Gerald Ford was the first and only Eagle Scout to be president. Bill Clinton and GW Bush were cub scouts. Since the inception of scouting in 1910 nearly all of the presidents have had some realtionship to scouting, often as adult leaders.