The E150 is a legaly coloring, wich is used in manufacturing Scotch Whisky etc.
There for it's only to give a production of whisky a uniform color.
I personally give the preverences of natural color, so you realy see the whisky how it is in reality, guess wich cask they might have used etc. but that's just personal. Like Rudolph said: there are more then 100 replies on coloring. In a way there's nothing wrong with that, but it gives you a feeling that the companies might hide something.....