The Transparency Law's been in place in the UK and the rest of the EU for around 25 years and simply put, it states that you cannot advertise any of the age or maturation period of a blend, except the youngest.

This means that blenders can’t share all the details about their creations. Therefore producers cannot be as transparent about what exactly they put into their blends as they would like to be.
They broke down every cask that was included in their blends, as well as how much they used and tasting notes for each. For most, if not all Whisky enthusiasts, this is something intriguing, adding a little bit of insight into some fantastic drams.
Compass Box says they wanted nothing more than to engage with their customers and give them the chance to experience every barrel in the bottle.
However, the Scotch Whisky Association soon notified them that they were breaking the law and they had to change the packaging. This sparked a campaign to transform the law, led by Compass Box and supported by Bruichladdich.
Why does the law even exist?
This law is in place to stop shameless producers from exploiting the nature of blends. Since blends are concoctions of different grain and malt Whiskies, you can add as much or as little of anything that works.
That means that without the transparency law in place, you could plausibly (and people have done it in the past) put a drop 25 year old in your blend and call it all 25 year old, when in fact it is mostly made up of much younger Whiskies.
So in reality, the transparency law is there to protect the consumer, despite how it may seem.
A reply of "it's a secret" to a request for more information on the blend can seem reluctant to engage with audiences. If you gave a similar reply to your wife when she asks how much you drank last night you might just understand their fear.
Another reason to change the law is the use of caramel colouring in Whisky. At the end of the maturation process the food colouring E105d aka caramel colouring is often added to the Whisky to produce a browner colour.

This colouring has no real effect on the Whisky or its flavour. It is simply used to change the colour and increase consistency or to make it look darker so people will perceive as a higher quality or older.
However, some customers are sceptical about the use of colour, which is fair enough and if you have any doubts yourself, the best thing you can do is read up on it and decide from there.
Currently only Germany and Denmark have laws stating the added colours must be declared on the bottle and with a new transparency law, this could change for Whisky everywhere.
So what do you say - how much do you want the producers to tell you about their Scotch?