The Scud Fly pattern is fantastic in any color you choose to use. Scud Flies excel in nutrient-rich trout streams below reservoirs and spring creeks, and can also be used where scuds are found in lakes and ponds. They’re often found fairly shallow and in and around weeds, but they’ll also live in both rocky riffles and slower, silt-bottomed areas.
The best times to use scuds are early or later in the fly fishing season. When you are fishing several nymphs patterns together, scuds are a good choice for the point fly. They work great for your euro nymphing rig set up or Czech nymphing.
I like to carry a few of each color, so I can match the naturals.