 Addition of manganese-II produced a second broad peak to appear at the red end of the emission spectrum at the expense of the antimony peak, excitation energy being transferred from the antimony to the manganese by a non radiative process and making the emitted light appear less blue and more pink.Replacement of some of the fluoride ions with chloride ions in the lattice caused a general shift of the emission bands to the longer wavelength red end of the spectrum.These alterations allowed phosphors for "Warm White", "White" and "Daylight" tubes, (with corrected color temperatures of 2900, 4100 and 6500 K respectively), to be made.