Tail: Mallard, two fibers
Body: Brown, mixed with yellow, mohair
Hackle: Black-red
Wing: Brown mallard, or hen pheasant’s tail
The Stone Fly from The Art of Angling by William Blacker. The one above is tied in hand on a vintage blind-eye hook, while the three below all are tied for fishing on Ahrex FW580 #10.
The color-combination here with the dark wing over the yellow-red body will result in a fly that should attract trout anywhere.