does color matters?

does flyline color matters? this is a long debating question in fly presentation. Over years, I found myself have leaning toward the camp of "Yah, it's matters"... as we all knows presentation is everything in trout fishing, stealth approach, good position, accurate casting, good landing, mending and good drift... all accounts! and everything is essential and important to a successful trout fishing. If you only fish for small creek pocket waters, you probably want to stop reading here... because you don't need anything below... For spooky trout fishing, I feel I need to do everything right in order to lure them to eat my fly. Does flyline color matters? I say yes!
As we know, trout has very good eye sight, not only see the full spectrum of color RGB as we can sees, but also studies show that rainbow trout can see the UV light (and most likely so in other trout species) that human can't see. On top of good color discrimination, trout also has a very accurate, sensitive vision, otherwise they will have a hard time to pick up a size #32 midge pattern. When we talk about vision and perception, there is one important factor that has to be taking into account, that is background color. Imagine a sculpin or darter swimming above a pebble bottom or on a white sand bottom. The background color will make them looks very different. Underwater trout looks up for food, the sky color become a predominant background color to them. So the contrast against sky color become important in trout fishing. White line will become camouflage under cloud cover. clear line will cast less shadow into the water under a sunny condition. The good old saying - "fly size" first, follows "shape" and "color"? have ever spooked a trout by casting a shadow into the pool? So the idea of monic flyline is by using a clear flyline, it will reduces the shadow and contrast when casting to a spooky trout. I have read some technical fishing reports in french nymphing for spooky trout. People are using long leader that up to 16-20 feet. Well, this might not sound difficult to cast to a experienced angler, however, the problem and challenge of this method is not casting, but is the lost of controlling the long leader. In my opinion, good control of the line and fly are the most crucial things in trout fishing. The solution? I am thinking the monic clear floating line maybe will provide a better control and stealth for this type of fishing... The drawback? they are more invisible to angler too, so a good feel in casting is needed, need some night casting training : ) The result? not sure yet... I will have to try it later in the trip and see how far it will go...