Abstract Multi‐primary color (MPC) technology is generally used to increase color gamut [1–2]. But, in this paper, MPC technology was used to enhance luminance better than conventional Liquid Crystal Displays (LCD) with 3 color RGB sub‐pixel. We have proposed 4 Primary Color System that has additional yellow(Y) color with an asymmetric sub‐pixel structure. The asymmetric sub‐pixel RGBY structure LCD has 18% higher luminance efficiency than conventional RGB LCDs under the same power consumption. This paper shows the improved luminance by multi‐primary color technology (RGBY).