The Silver Wilkinson Salmon Fly in all of its various tying styles is considered a  good fly to use when the water is carrying some colour or on heavily overcast days. These sort of conditions reap the benefit of the bright blue and magenta colours and the iridescent tinsel that gleams in the murky water.  This pattern has a long history; first tied in the late 1850s by its originator, the Reverend P. S. Wilkinson, it was used on the Tweed with great effect and continues to this day 150 years later.