The Yellow Stimulator has to be the most popular color of them all. We highly recommend it in summer when Golden Stones, hoppers and Yellow Sallies are available food items and on the minds of trout. Stimulators get the call for so many situations it's hard to know where to start. They serve well to imitate various hatches but are probably most used as an attractor dry fly while searching for active fish looking for a big meal. Every angler should have an assortment of Stimulators in various sizes and colors. Size 10 pictured.