Coffee roast color analyzer

There was one thing about Kuwait, All of the supermarkets had a set up with a dozen different kinds of coffee beans roasted to perfection some bean were a dark green after roasting while some were nearly black it all depended on where they were from. On the booths were blend charts listing how many grams of which beans were required to make a specific blend or you could ask the attendant to blend your own mixture. I've only seen something like that here in the USA at specialty coffee houses and a couple of very high end super markets.
Color is not always taste correct but close when you only have a limited selection of beans to roast them yourself.

Coffee roast color analyzer - GIF