Does the wing look like it is only one material or maybe two? There is product called "Angel Hair" which is fine, straight, and in Polar Blue gives off a sheen you describe. It is often added to a wing of zlon or antron to give it a little shine. There are a number of similiar products out there that have a similiar effect.
Tend to agree with some of the previous posters who argued that materials are not the sole determinant of the effectiveness of a fly...but then again, every so often, some patterns seem to work much better than others, so good luck with your quest.