Something that should be considered is that many other strains show low levels of anthocyanin production, without any potential of crossing to OSU (or other "blue" strains). Sepal and leaf coloration is common. In particular, sepal coloration is present in var "Tiny Tim" and appears to be derived from the Solanum pimpinellifolium parent. The genes that result in the blue color of the OSU and derived strains have homologs in basically every other wild species which modern tomatoes were bred from. These genes can assort into combinations that result in enhanced anthocyanin production (
http://the-biologist-is-in.blogspot....ue-tomato.html) without any potential crossing by OSU or related strains.