The color of a fly line is considered by most anglers to be an unimportant issue. That’s
because in a perfect world, the fish never sees you fly line. Of course, the main purpose
of the leader is to make sure that the fish doesn’t see the fly line. Of course, the fish may
very well see your fly line and in those cases probably a less visible fly line would be
probably be preferred.
Since a floating fly line is viewed by the fish silhouetted against the sky, lighter shades of
fly lines may be less visible on clear, blue-sky days, whereas, darker shades of fly lines
may be less visible on dark, cloudy days, or early and late in the day. Wet or sinking fly
lines are probably more visible to fish than floating fly lines and darker shades of colors
are generally considered best for those types of fly lines.
Several manufacturers have developed fly line colors that are designed to be as
inconspicuous as possible under the specific conditions that are normally encountered
when you are fishing for certain species. Some of the newest saltwater fly lines are clear.
To date, to our knowledge the clear fly lines all sink and no one has come up with a
clear, floating fly line. Also, although I fail to see any difference in them, the only clear fly
lines on the market to date are designated for saltwater use. That should not make any
difference.
Something I personally don’t like at all are some of the extremely bright colored fly lines.
Fluorescent colored fly lines spook the fish your tying to catch in many cases and under
most circumstance. A bright orange, red, or yellow fly line makes it easier to see the line
but I fail to see why it’s difficult to see most any color fly line.
If you “line a fish”, meaning you cast the fly line directly across the fish, most of the time
you will spook the fish regardless of the color of the fly line you use. The problem
involves just how close you get the fly line to the fish and how deep the fish is. Fish near
the surface have a small window of vision due to the refraction of light. Fish deep in the
water have a large window of vision but couldn’t see the fly line as well as they could if
they were close to it and it was within their window of vision.
This point can be argued differently and different anglers have different opinions on the
effects of color of a fly line. I just don’t understand the need to use anything but subdued
shades of colors of fly lines. I see absolutely no advantage in the bright colors.
I think it’s mostly like almost everything else and the colors are far more for the anglers
than anything else. Never-the-less, it’s a fact fly lines come in every conceivable color
you can think of.