Multi-layered thin films of $Fe_2O_3/Na_3AlF_6/Fe_2O_3/Cu$, Cr, Al were deposited on glass substrate by evaporation process. As high and low refractive index material, $Fe_2O_3$ and $Na_3AlF_6$ were selected and additionally Cu, Al and Cr were chosen as mid reflective layer respectively. Optical properties including reflectance were systematically studied depending on optical thickness of $Na_3AlF_6$ especially $0.25{lambda}$ and $0.5{lambda}$. In order to expect the experimental result, the simulation program, the Essential Macleod Program(EMP) was adopted and compared with the experimental data. Based on the results taken by spectrophotometer at viewing angle $45^{circ}C$, the $Fe_2O_3/Na_3AlF_6/Fe_2O_3/Cu$ show the colour rage between red and orange in $0.25{lambda}$ and green and pupple in $0.5{lambda}$ respectively. When the Al was used as mid reflective layers in $Fe_2O_3/Na_3AlF_6/Fe_2O_3$ system, typical yellow colour and mixed colour between green and pupple were appeared in $0.25{lambda}$ and $0.5{lambda}$ of $Na_3AlF_6$ respectively. As compared the experimental result to simulation data, it was found out that the experimental data is relatively well matched with the EMP simulation data.