[tde-users] Monitors plural gamma channels plural?

I have been trying and failing to get my three monitors, two of which are ancient and all of which are different, to produce matching colors. I'm using the NVIDIA non-free driver. For purposes of this discussion let's ignore the hardware color controls (which are inadequate). I can use the NVIDIA X Server Settings utility which has excellent controls for R, G, and B but intermittently tells me that something else has changed the color settings. I can use Trinity Control Center / Peripherals / Display but the Monitor Gamma function affects all three monitors simultaneously. Unlike other gamma controls that seem to prefer a number near 2.2, this seems to prefer a number near 1. I can use Trinity Control Center / System Administration / / Monitor & Display which purports to control the three monitors separately but the instant I move any gamma control by the smallest increment my right-hand monitor (no matter which monitor I have selected) looks like a 1980's CGA display. (This can be fixed by rebooting or by starting the NVIDIA X Server Settings utility.) There is also Trinity Control Center / Peripherals / Color Profile which I have not used, and where everything is unchecked in hopes of not confusing myself even further. I have been unable to find anything online by searching, although some CGA-like scrambling was mentioned in passing in this thread: https://www.spinics.net/lists/trinity-users/msg11883.html Can anyone point me to information on how TDE gamma controls work, how they are supposed to be used, and/or how to stop whatever in the background is overriding NVIDIA X Server Settings? Thanks! --Mike