In a previous work [J. Opt. Soc. Am. A29, A209 (2012)], we presented a visual color discrimination experiment whose results established the existence of a relationship between the correlated color temperature (CCT) of a light source and the color discrimination capacities of the observers. The results indicated the existence of a statistically significant difference in the color discrimination of unequal sample pairs when using light sources of different color temperatures, with the discrimination capacity being greater the higher the light source's color temperature. That previous work employed an RGBA-LED light source configured with three color temperatures: 2800, 5000, and 6500 K. In order to go a further step in this line, this work expanded the range of color temperatures up to 9700 K. The results showed that there is an optimum CCT of around 5000 K at which observers were found to have a greater color discrimination capability.