The Indigo series includes the Blue Beauty Tomato, a unique variety with blue, almost black skin. Created at Oregon State University in the 1960s, these tomatoes were bred by crossing cultivated tomatoes with wild species from Chile and the Galapagos Islands. The young fruits develop indigo-purple skin when exposed to sunlight, thanks to the presence of Anthocyanin, a powerful antioxidant found in blueberries. The Blue Beauty Tomato is ready to harvest when the skin turns bright rosy red on the bottom, while the shoulders start out sapphire blue and darken to a deep purple-red as they ripen. These meaty slicing tomatoes weigh 6-8 oz and grow in clusters, with excellent resistance to cracking and sunburn.