Calico is not a breed of cat, but only an expression of their coat color; many cats have calico coats, such as American Shorthairs, British Shorthairs, Cornish Rex, Devon Rex, Maine Coon, etc.
Due to the unique chromosome combination responsible for their tri-color coat, calico cats are almost always females. Because of this, they are less likely to trigger allergic reactions in humans in general.
Still, They Are Less Likely To Trigger Allergic Reactions