[SOLVED] PC Color / Nightlight issues

[Savage One]

Hi, I'm troubleshooting for my little brothers PC.

He pretty much always has the windows night light on as he gets eye strain pretty easily. This morning when he turned his PC on everything was pink. First bits of troubleshooting revealed it was the night light doing this.

After turning it off or reducing it's strength, it turns out pretty much all colors are messed up. Particularly all reds/oranges/yellows are really overblown and saturated. Some greens as well. Blues are all the wrong shade.. ect...

This is where I'm stuck at. I've done a lot of troubleshooting and I've come to think it's either the GPU or the Monitor, but as this isn't my PC I can't really just test it as new ideas pop into my head, so I'm looking for some suggestions for what to try when I test further later.

Troubleshooting so far:

-Reinstalled NVIDIA drivers
-Checked the windows color scale settings / windows themes
-Windows health check services (SFC /scannow, DISM component cleanup/ scanhealth ... ect...)
-Booting into safe mode (issue persisted)
-Looking in the BIOS I'm not convinced that the colors were messed up there as well, but I'm not convinced that they were accurate either. 50/50

I intend to test with another monitor / GPU later but again, I don't really "just have" access to this PC, so I'm hoping for some ideas to take with me to try.

Relevant specs:

Windows 10
3070 Ti
EVGA 700w PSU
Ryzen R5 5600x

I'd be glad to elaborate on any information here, any suggestions will be much appreciated. Thanks!

 

[Savage One]

Upon trying another monitor. The problem was fixed. Further inspection revealed it needed a new HDMI cable. Hopefully this helps someone, kinda ashamed that I missed something that obvious earlier.