PANI-V2O5 nanocomposite is a promising electrochemical platform due to rich multi-redox activity of both the constituents. However, prior studies have largely focused on PANI-mediated pillaring of the V2O5 (001) plane, leaving the electrochromic potential of non-basal planes unexplored. This study reports strategic synthesis of 5-20 wt% PANI loaded V2O5, that induces pronounced preferential growth along the V2O5 (110) plane, and oxygen vacancy engineering leading to markedly enhanced electrochromic performance. An optimized 10 wt% PANI composition delivered ultrafast switching (tb = 0.03 ± 0.005 s; tc = 0.04 ± 0.005 s), while 15 wt% PANI enabled four highly reversible color states (yellow → green → brown → orange) with an exceptional optical modulation of 83.9% at ∼ 400 nm. Density Functional Theory (DFT) revealed that PANI-induced oxygen vacancies restructured the electronic and ionic landscape by generating mid-gap states, increasing carrier density, and lowering Li+ diffusion barriers. Projected density of states, corroborated by Raman and FTIR analyses, confirmed strong hybridization between PANI π -orbitals and V dxy states, enabling efficient interfacial charge transfer. This synergistic coupling yields rapid, quadri-colored, high-contrast electrochromism, advancing towards next-generation tunable optoelectronic devices.