Yes I do chage it out my Tygon annually, and thats why I wanted to do a color code...I got my vent and clunk lines crossed last time. Oh what fun it was trying to run the good old reliable G-62. It took me a few minutes to discover my error. I was almost desperate enough to get some plain old black fuel hose from the auto parts store.
Now...one blue (vent), and one yellow (clunk), will keep things clean and simple.
thanx again.