An organic light-emitting diode (OLED) display panel includes: an OLED layer; a color filter layer; and a color coordinate tuning layer disposed between the OLED layer and the color filter layer, wherein the OLED layer includes a first light-emitting portion comprising a first light-emitting layer configured to emit a first light and a second light-emitting portion comprising a second light-emitting layer configured to emit a second light. The OLED layer is configured to emit a third light produced by mixing the first light and the second light. The color coordinate tuning layer is configured to output a fourth light different from the third light. The number of all of peaks and shoulders that an EL spectrum of the fourth light has is higher than the number of all of peaks and shoulders that an EL spectrum of the third light has throughout an entire range of a visible wavelength band.