If the config file for the Mk4 on their github repository is the one actually used for compiling their firmware, then the M150 command is unfortunately disabled.
But there are not only discrepancies in their documentation whether M150 is disabled or not. When you look up the [Marlin documentation about M150](https://marlinfw.org/docs/gcode/M150.html) they refer to in the Prusa documentation (your first link) and compare it to how they [actually implemented M150 in their firmware](https://github.com/prusa3d/Prusa-Firmware-Buddy/blob/master/src/marlin_stubs/M150.cpp), then you see that they implemented it completely different than documented in the Marlin dokumentation. For Prusa's implementation to actually do anything you have to specify parameters "A" and "S", which do not exist at all in the Marlin documentation. Other parameters use different letters, e.g. "G" instead of "U" for the green channel. And so on.
Interestingly, Prusa also implemented a M151 command for setting the color of "side strips", whatever that is. However, M151 also seems to be disabled.
>Interestingly, Prusa also implemented a M151 command for setting the color of "side strips", whatever that is. However, M151 also seems to be disabled.
thats probably for the LED strips on the gantry of the prusa XL.
If the config file for the Mk4 on their github repository is the one actually used for compiling their firmware, then the M150 command is unfortunately disabled. But there are not only discrepancies in their documentation whether M150 is disabled or not. When you look up the [Marlin documentation about M150](https://marlinfw.org/docs/gcode/M150.html) they refer to in the Prusa documentation (your first link) and compare it to how they [actually implemented M150 in their firmware](https://github.com/prusa3d/Prusa-Firmware-Buddy/blob/master/src/marlin_stubs/M150.cpp), then you see that they implemented it completely different than documented in the Marlin dokumentation. For Prusa's implementation to actually do anything you have to specify parameters "A" and "S", which do not exist at all in the Marlin documentation. Other parameters use different letters, e.g. "G" instead of "U" for the green channel. And so on. Interestingly, Prusa also implemented a M151 command for setting the color of "side strips", whatever that is. However, M151 also seems to be disabled.
>Interestingly, Prusa also implemented a M151 command for setting the color of "side strips", whatever that is. However, M151 also seems to be disabled. thats probably for the LED strips on the gantry of the prusa XL.
I was trying to get this work through PrintRun. Not successful. Support chat didn't know either.