I tie my dark sulphur nymphs based on Dan Shield’s pattern. His is a blend of 60% dyed brown Australian opossum( I’ve been using Hare Tron Dubbin dark brown #16) and 40% orange sparkle yarn. I use Aunt Lydia’s orange sparkle yarn which I cut up in tiny pieces and mix by hand with the brown dubbing. I’ve used this with great success on Spring Creek and the Little J. The darker brown on the left would be good for the dark nymph. The lighter nymph, based on a, I think, a George Harvey pattern, is more of a tan like the Hare Tron Dubbin or a tan dyed rabbit or Hares Ear plus #7.