Two tridentate chelates derived from functional 1,3-dipyridin-2-yl benzene, i.e. 1,3-difluoro-4,6-di(pyridin-2-yl) benzene (L1-H), 1,3-difluoro-4,6-di(4-t-butylpyridin-2-yl) benzene (L2-H), 1,3-di(pyridin-2-yl)-5-t-butylbenzene (L3-H), and 1,3-di(isoquinolinyl)-5-t-butylbenzene (L4-H), and 2-pyrazol-3-yl-6-phenylpyridine, i.e. 2-(5-trifluoromethyl-1H-pyrazol-3-yl)-6-(4-trifluoromethylphenyl) pyridine (L5-H2) and 2-(5-trifluoromethyl-1H-pyrazol-3-yl)-6-(4-t-butylphenyl) pyridine (L6-H2), are synthesized. These chelates are classified as the monoanionic and dianionic chelates according to the number of active hydrogen atoms present. Treatment of L1-H - L4-H with IrCl3∙3H2O afforded chloro bridged dimers [Ir(Ln)Cl(μ-Cl)]2 (n = 1 - 4); upon incorporation of secondary chelates L5-H2 and L6-H2, it gave formation of six judiciously selected, charge-neutral, bis-tridentate Ir(III) complexes, cf. [Ir(L1)(L5)] (1), [Ir(L2)(L5)] (2), [Ir(L3)(L5)] (3), [Ir(L3)(L6)] (4), [Ir(L4)(L5)] (5), and [Ir(L4)(L6)] (6). Detailed characterization and photophysical measurement have been performed, and computational calculations were executed to shed light on the enhanced emission efficiency and color tunability. This work further investigates green-emitting and red-emitting organic light-emitting diode (OLED) applications of Ir(III) complexes 1 and 5, respectively. As a result, a maximum external quantum efficiency of 13.2%, luminance efficiency of 41.4 cd/A, and power efficiency of 35.5 lm/W was obtained for the green OLED (complex 1), as opposed to 15.4%, 21.0 cd/A, and 16.3 lm/W for the red-emitting OLED device (complex 5). The high electroluminescence efficiencies suggest great potential of the titled complexes for applications in multicolor OLED displays.