A lamp having improved color quality scale is provided. The lamp has a light-transmissive envelope and a phosphor layer comprising a first phosphor and a second phosphor wherein the first phosphor has an emission band with a maximum between 590 nm and 670 nm and the second phosphor has an emission band with a maximum between 520 nm and 570 nm. The light generated by the phosphor layer, when the lamp is energized, has delta chroma values for fifteen color samples of the color quality scale within select parameters. The delta chroma values are measured in the CIE LAB color space.