[silver creek]

I also recommend cleaning the line and using Scientific Anglers Fly Line Treatment or another treatment.

As to what weight of line, I agree with the 6 weight.

As to color, all fly lines are seen against the background of the sky or vegetation when they are being cast. When the line is floating, fish see the underside of the line against a brighter sky. So they see a silhouette of the line and perhaps a bit if the color.

I personally like the green color of Cortland 444SL Classic fly line. My rule of thumb is that a fly line should be no brighter than a shirt you would wear when fishing for picky trout.