is observe on different coordinate of the chart\[32\] as shown in Fig. 3. Finally it gets saturated at dark blue colour and their corresponding coordinate on CIE chart are (0.16, 0.12). Hence except blue color, device absorbs all colors in its ON state. The CIE chart is very useful as it says that if somehow the material, to be used in device, is tuned in such a way that the color corresponding to coordinates (0.5,0.5) is allowed to transmit from the device a red color appearance will be observed. If one identifies the species responsible for appearance of one particular color corresponding to a given coordinate, the same can be used to make a devise giving that particular color. Before implementing this idea, it is very important to understand the species responsible for a particular color’s appearance. This investigation can be done using Raman scattering experiments.

![Figure 6: In-situ UV-Vis spectroscopy coloration and de-coloration cycle or absorbance change by biasing ON and OFF state within a time period. Inset image for static analysis of change in transmittance. ](figure6){width="10cm"}

Figure 4 shows Raman spectra of the device in its OFF and ON states. Raman spectrum of the device in its OFF 