Having troubles with colors changing for GPC

[September]

Between different PC's I'm getting different colors for the same web page. Some are Intel GPU, some AMD and some nVidia (both pro and gaming). I've even noticed a difference on the same PC after upgrading from an nVidia GTX 770 to a GTX 1060. Really need the GetPixelColor to be consistent between these machines, or at least reproducible. What settings do I need to check, is anyone away of Windows or driver settings that impact this?

Two PC's are running Dell 27" 1440p monitors, but this is happening across a variety of desktops and laptops.

[Dorian (MJT support)]

If I try getPixelColor on two different laptops on the same image (I used the blue button on the MJT homepage) I get two different value too.

This is somewhat to be expected unless each PC has identical colour profiles, graphics settings, any calibration is identical, and you have identical hardware.

Achieving this is likely to be extremely challenging.

You may simply have to re-sample the colours on each target PC.

[September]

So I've figured something out, can't have this problem between my desktop PC's especially when they are so similar. In fact they both worked, then I moved the GTX1060 from one to the other (replacing a GTX770) and it stopped working, while the other machine got a new GTX3080 and kept working. So clearly some kind of driver or setting. I was unsure what exactly Windows 10 had done after the upgrade so I re-installed clean nVidia game-ready drivers which is what I was using before. No luck. Then tried the studio drivers, still no luck. Oddly enough a brand new driver came out so did another clean install with game-ready drivers, played with color settings (Accurate vs. Reference override in nVidia Control Panel - no difference, left on Accurate).

This is what eventually fixed it: Under Windows Control Panel, search for "Calibrate.." and run the Windows calibration tool, just click through all the steps of the wizard without touching anything, skip the font wizard at the end, and click Finish. This installs a new color profile into Settings | Display | Color Profile called "sRBG display profile with hardware configuration.." in addition the the "Dell Model XXXX Color Profile, D6500" which had been the only prior choice. Seems like the new video card/drivers/Windows created that Dell entry automatically and the only way to get the standard sRGB profile is to run through that wizard! Problem solved.

[Dorian (MJT support)]

Thank you for the update. I'm sure that will help others.

[September]

Yes, in fact this fixed two laptops as well, one brand new and one over 10 years old. I believe this is something new from a Windows 10/11 update during the last few months.