Yeah, I too think UG is your best bet at foolin fish in low, clear-ish water to eat your gear. If it is harder to see the line while underwater, you have better odds of hooking up for sure. Funny you ran Cajun too. I see a lot of guys who first start out with that stuff. Must be old habits or something.
I have seen two varieties of pink lines in Canada so far. One was essentially a translucent pink color, and the other was surely just a neon red hi-vis line. The pink translucent stuff, I have fished with guide friends who swear by it too. I think in some of the really blue, glacial creeks, and rivers, it does darken up a lot, and blend in with low light fishing conditions that are so prevolant in middle B.C., but I don't think they fish it when the sun is on the water. They are treating it like Maxima's Chameleon sorta. Fish it at first, and last light, but not in the daytime aparantly. Thats pretty much all I can say about what I know of that pink line.