Yes, Firenzecolor appears to be a legitimate company. They have a presence on Houzz, a reputable home design platform, where they have received positive reviews. They offer a range of products, including lime-based paints and plasters made with traditional recipes, marble dust, clay, minerals, and organic pigments. They also provide workshops for all skill levels. However, it's always a good idea to do your own research and read reviews before making a purchase.