Eu2+, Mn2+ singly and co-doped Sr2−xCaxP2O7 phosphors (x = 0–2) are prepared by solid state reaction. Crystal phase evolution is studied as a function of Ca2+ content based on the experimental measurements of X-ray diffraction, photoluminescence and fluorescence decay. The x dependent emission band shapes and peak positions for both Eu2+ and Mn2+ are discussed in terms of the crystal phase types and crystal field strength in relation with Ca2+ substitution for Sr2+. An effective energy transfer from blue emitting Eu2+ to orange emitting Mn2+ is observed in all compositions beneficial to dual color emissions. The widest emission band and intense orange emission are found in Sr1.25Ca0.75P2O7: Eu2+, Mn2+, exhibiting promising use in white light generation using near UV LEDs.