The edible swatch-style tarts are made from various berries, bananas, carrots, lemons and sweets on a sweet pastry base that is iced in white and has the pantone colour code detailed. This page has pictures of all the tarts – hope your French is better than mine!
I like the shades of blue on the tart that I’ve pictured here and my other favourite is the one with the raspberries (Pantone 1797 C). I wonder if the tarts were eaten once all the photos had been taken?
Take a look at this wikipedia page for a more detailed background to what Pantone is all about.