The Whisky cask and the colour of the Whisky
The whisky cask alone is responsible for the colour of the distillate!!
Former bourbon casks as well as former white wine casks just leave rather pale traces of colour. Former sherry casks (especially Oloroso or PX) as well as former port or red wine casks give the maturing distillate a strong colour. Of course, maturation time as well as the quality of the cask (1st fill or 2nd fill) also is of great importance.