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.
Ulysses S. Grant in Ireland. The first president to visit Ireland was no longer president when he arrived in Dublin in 1879. Ulysses S. Grant had dominated the American political scene for well over a decade. By the end of the U.S. Civil War he was Commanding General of the Union Army.