..."if Scotch whisky is only supposed to be made from certain cereals, water and yeast, and aged for a minimum of 3 years in oak barrels not exceeding 600 liters, how and why is it allowed that caramel coloring is sometimes added?"
It may be that some of the posts/posters are confusing the sequence of events for traditional whisky production: i.e. addition of coloring agents happens AFTER distillation and aging and thus caramel shouldn't be thought of as a basic ingredient like malt, water or yeast. -But perhaps this is a distinction without a difference for many malt people, and I can understand their dismay at a spirit being presented in anything but the unadulterated (to their mind) form that best represents that particular malt/expression. For myself, tho' it's nice not to have coloring added, I don't get my knickers in a knot over it.