Mercury vapor discharge fluorescent lamps are provided. The lamp can include a lamp envelope enclosing a discharge space and having an inner surface. First and second electrodes can be positioned on the lamp, such as on opposite ends of the lamp envelope. An ionizable medium that includes mercury and an inert gas can be within said lamp envelope. A phosphor layer can be on the inner surface of the lamp envelope. The phosphor layer generally includes a phosphor blend of a calcium halophosphor, a blue phosphor having an emission peak at about 440 nm to about 490 nm, a blue-green phosphor having an emission peak at about 475 nm to about 530 nm, and a red phosphor having an emission peak at about 600 nm to about 650 nm.