The last few times I have hooked up to city water in a RV park I have found the first basin of water I run into the back bedroom sink is green, almost the color of transmission fluid. It only seems to...
Green water can be caused by copper plumbing fixtures or pipes, that is off PH water has set in for a time. As the copper corrodes or oxides, it make the green color. Just a guess, as most RV plumbing is plastic.