Spotted Fly Yellow Black Panther Martin spinners use bright contrasting colours to make each spinner as visible as possible to fish, even during low light conditions and in discoloured waters. Salmon, steelhead and trout fishermen often have some of the best fishing when its raining and overcast. Poor water clarity of less than two feet usually triggers these fish to strike. Spotted Panthers are also effective for other gamefish early and late in the day, when it is overcast, or when the water gets murky from wind action.