Color Temperature Mode allows us to set the colors of the lights in the scene with Kelvin values instead of RGB values. For example White is 6500 Kelvin according to the D65 standard. Candle light is 1800 Kelvin.
Using color temperatures is a more convenient way to set realistic light colors so here is how to do it!
After fiddling around for two days with installing packages, adjusting configs and restarting services, I finally got GitLab to work on my Virtual Server with Plesk Onyx and SSL encryption. For anyone having the same idea, here is how I did it step by step.