How to configure Windows RDC to use 16-color mode?

I seriously need to minimize the "eye candy" traffic overhead and only leave the graphics quality enough to actually manage the server. I've like to switch to 16 or 256 color mode if possible but the lowest color depth offered by the client settings is 15-bit High Color. Is this possible to overcome?

The problem is that the app I need to configure on the server side is a stupid surveillance dashboard and it always displays 9 real time video streams all the time it is open (though I only need to adjust its settings) giving a pure zen training experience.

I have found the answer myself, so sharing it for further reference of whoever may need it.

The solution is to open the .rdp file (%USERPROFILE%\Documents\Default.rdp by default) and edit (or add if missing) the following line:

session bpp:i:8

The number (8 in this case) sets the color resolution in bits per pixel. 8 (for 256 colors) is the lowest value available through manual editing (while the lowest value available through the RDC GUI is 15).

Other .rdp file commands can be found here.

PS: I am also glad to mention that my practical problem (unintentional but unavoidable video streaming jamming the whole RDP channel) is solved completely! The thing works lightning-fast now. So the idea to lower the color depth was right what I needed.

Go the the Experience tab in the RDP client and set the connection speed to: Modem (56kbps).