Thank-you one and all for your helpful suggestions. After reading Michael Radencich's books I did use dyed pheasant collars for a while, but then I began to consider the pursuit of perfection, at least in my own case, was verging on OCD so I sold all my rare feathers, carefully gathered over several decades, to other, better tyers of classic salmon flies than I will ever be. Switching my efforts to classic Dee and Spey flies after reading the fabulous books by John Shewey and Bob Verveka, I have made a decent fist of some of them. It happens that in my modest collection of "trophies" I have a gut-eyed double Popham adorned with at least five genuine Indian Crow feathers which must be 120 years old, and my goodness, how they still glow. Then I came across the Jock O'Dee in one of these books which specifies an IC tail. I tied it with a dyed pheasant collar a few years ago but unfortunately it has faded somewhat. Revisiting my earlier good intentions, I have decided to mend and make do rather than use another precious heron hackle to tie a new specimen, so here is the master plan: with careful manipulation and under substantial magnification, I shall liven up the offending tail with fine-tipped permanent felt pens in the appropriate colours. This approach will I think bring sufficient satisfaction to keep my OCD at bay. I may well adorning the remnants of my dyed pheasant collars similarly, to avoid further gnashing of my ageing dentition! Thank-you all again, especially Fruin, who clearly put a lot of thought into his reply!