My work LCD monitor has four settings for Color: 

* warm (5000K)
* standard (6500K)
* cool (9300K)
* custom (each of the RGB values can be chosen separately)

What is the setting that could reduce at most blue light? I mean: changing color temperature would effectively affect the amount of blue light emitted, or it's just a graphic setting?

Or it's changed somewhere else on the monitor? Note that the monitor doesn't have a Blue Filter on/off option, otherwise I'd already have set it.

I'm not interested in software solutions - such as [f.lux](https://justgetflux.com/) - because I am not allowed to install them.