Typically the smoked haddock you get in a supermarket has been dyed to give it that richer yellow colour. It adds nothing to the flavour and is artificially created so it is far best to sourse your smoked haddock from a fish specialist if you can.
Many smoke houses sell their ware on the internet so here are a few you can buy directly on line from.

Messers J.Smith, Sandend
Messers J.Smith Some of the best smoked fish in Scotland. T: 01261 842419 Seafield Road Sandend AB45 2UF Facebook Page

Sutherlands of Portsoy
Sutherlands of Portsoy Based in the small fishing town of Portsoy in the North-East of Scotland, Sutherlands produce the finest Smoked Salmon for discerning customers

Downies, Whitehills
Downies of Whitehills Downies of Whitehills is a long established family business that can trace it’s roots back more than 120 years. As a supporter