Comparing the CIE diagram for complex 3 we see a shift in the CIE coordinates from the white region at 300 K to the yellow region at 15 K (Figure ). In complexes 1 and 2, we see a shift from the blue to violet-blue region and a shift from the greenish blue to blue region, respectively, when we increase the temperature from 15 K to 300 K (Figure ). The shifts in the colour coordinates are due to the changes in the spectral patterns of the emission profiles of the complexes on temperature variation and, hence, further reinforce the property of thermal sensitivity of these complexes.