Regardless of whether you are trying to match the Sulphur Ephemerella invaria or the slightly smaller Ephemerella dorothea, they all have yellowish, yellowish green, or orange/yellow bodies. They all hatch in the evening or occasionally during mid-day on a cloudy day. This soft hackle bead head wet fly version is perfect for fishing on the swing as the hatch is beginning and the fish have not yet risen to dry flies. Color, Sulphur. Fly in sizes: 16, 18.