Windows Vista’s Gamma Table Bug

Windows Vista has a new color-management/profiling format called Windows Color Systems. It purports to offer advanced color management and better results than the age-old (and forever dying) ICC/ICM color system. ICC has been buggy the whole way, with both political and technical issues plaguing its colorful history.

Windows Color Systems is a step in the right direction, but it comes at a very heavy price: Windows Vista no longer properly interfaces with ICC/ICM color profiles!

Anyone using the ATi Catalyst Control Center, BasicColor, ColorEye, Spyder, or any of dozen other color-management and gamma-correction programs available will have noticed the bug we’re talking about: once you lock your PC (winkey+L) the gamma LUT on your graphics card is reset.

ICC/ICM profiles have two different “parts” to them. The first is a color-correction section which “maps” the colors produced by the video card to match the correct color output as defined by your monitor. “Blue” on your monitor may be different from the “blue” on your mother’s – that’s what the monitor-calibration and gamma-correction software seeks to fix. Once you “regulate” the colors on your PC, you’re using the “real” blue, one that the color industry has reached a consensus over.

The second section of the ICC regulates the gamma output. In order to make certain colors match up, the gamma (more or less the amount of black/bright your display shows) is modified to tally-up with the correct settings. With properly-calibrated monitors, an image will display (almost) exactly the same – with the same hues, midtones, and shades; with the same brightness; and the same overall effect. Gamma plays a very important part in this, regulating the highly-varying brightness/contrast settings on monitors to produce the same image in the end.

With Windows Vista, when you first load an ICC profile, the correct color and gamma settings are applied. But when you lock the screen, log off, or do a bunch of other things, the gamma LUT is reset. The correct colors are still applied, but depending on your configuration your display might now be a garishly bright hue of green or blue!!

There is no fix, at least none that we can see. We’ve tried to apply the ICC profile to both the local account and the default system settings, we’ve disabled UAC and formatted and reformatted. We’ve tried it on nVidia and ATi, and it always happens: when you lock the PC, your gamma table is reset.

Microsoft has not yet acknowledged this issue (as a quick search for “gamma” or “ICC” in the Microsoft knowledge-base will reveal), but there is a workaround (though a poor one). The freeware DisplayProfile utility (donate to help cover hosting costs!) will show you a list of available ICC profiles and let you switch between them on the fly, but more importantly, it will also apply the gamma table settings as well.

DisplayProfile is a standalone executable. Just run it and select a profile other than the one you want to use, then switch back to the real profile in order to re-apply the gamma LUT settings. Just stick it in your quicklaunch toolbar, and whenever you unlock your PC run it to reset the gamma settings.

Hopefully Microsoft will address this issue with Windows Vista SP1 later this year. Until then, thank God for freeware!

132 thoughts on “Windows Vista’s Gamma Table Bug

  1. As I posted previously, I received a response from the Windows Experience Color Team saying the following:

    It’s a known problem (and has been known for a long time) and it’s caused by the fade-to-black transitions that Vista uses during login, resume, UAC check etc. The black fade is achieved by manipulating the gamma tables, but after the fade is completed the system fails to restore the correct values.

    There will not be a fix in Vista SP1, but the fix has been cleared for release as a Windows Update Hotfix shortly after SP1.

  2. “Shortly after” SP1 means exactly whatever long it takes, I bet two years more. So don’t count on it, just don’t buy Vista and use XP if you must or Linux (which has no color management as well).

  3. This gamma table bug was one of the major motivators for me to go Macintosh for my graphic design work. Trust me, I love Windows for what it does; but I need a reliable platform for color design work, and Vista isn’t it. Microsoft tried, really tried hard with their new color management system for Vista, but in the meantime, they left this gamma table problem with us. Many of us are experiencing it and have come here for answers. A few have not experienced it – it may be because of their graphic card drivers, or some other factor, perhaps.

    As I wrote previously, I’ve had some success anyway with Pantone/Gretagmacbeth’s Huey monitor calibration tool – it fixes the damage done by the Vista gamma table bug within a matter of seconds after the problem surfaces. So if I insisted on using Vista for design work, I could probably do it if I kept Huey plugged in and the calibration automatically refreshed every few minutes or so. It’s nice in the meantime to hear that Microsoft admits that there is a problem. It would be nice to see a knowledgebase article or some other official news from them.

  4. For what it maybe worth, after Windows Update ran this week (4/9/08) my problem with the color LUT being wiped out after sleep or locking windows has been resolved. I am running Vista 64.
    Windows installed 9 updates on the 9th, however none of them listed this problem or that it had been fixed.
    Anyway, I am glad that it is repaired. It was a major PITA!

  5. Not completely fixed here 🙁 32bit Vista Ultimate, fully patched.

    A UAC prompts still messes up the LUT

  6. Likewise on 32-bit Ultimate and Home Premium PCs, still whenever UAC, USB device insertion/removal, Office 2007 starting/Outlook 2007 downloading emails, etc…

  7. I wonder what update that was – the last WU totally ruined my computer and I must now format it… Keyboard no longer works from the bootloader selection screen onwards!

  8. When I frist began having problems, I shut off the UAC, and I dont have any Office products installed on my Vista 64 machine. I guess that is why that it appeared to be fixed.
    My Vista 64 machine is used solely for photo & video editing, I use my older XP box for general office and internet use. Perhaps one day M$ will fix the rest of the issues. Until then I will stay with my current setup.

  9. I got a question : I got only 1 Profile with gamma table tag in my list when i run display Profile and unfortunately it has the gamma settings “1” inside obviously, because if i switch to it, gamma is set to 1.
    Can i download somewhere any Monitor Profiles or a programm that creates usable Monitor Profiles?

    Monitor type : iiyama E2200WS

  10. This site is really helpful. recently suffered with same problem. I had been using Spyder2express on my hp dv6000 with intel(r) 945 chipset with Vista Home premium for almost 9 months and it was running beautifully. No change in color from hibernate or LUT.

    About 2 months ago, i installed the optional updates which was the intel driver. upon installing, the problem described here started showing. I rolled back the driver from the previous and it worked beautifully…until now.

    I had my laptop upgraded from 1bg memory to 2gb, the one who did the upgrade updated everything including the optional updates. Then turned off the laptop so i wasnt able to rollback the driver.

    Been trying to find the best solution without re-formatting and this by far is the closest (using the displayprofile).

    I believe the fault maybe on the graphic driver.

  11. I have a fully-patched Windows Vista Ultimate x64 with nVidia 7900GS card. I still have the problem. I tried uninstalling and reinstalling the update from MS that is supposed to fix the problem, and it still occurs. I lose the gamma table after hibernation, sleep, rebooting. Oddly, about one out of five times running Google Chrome causes the gamma table to reset as well. Weird! Anyway, for now I’m using DisplayProfile to restore my profile, but it’s a pain!

  12. Hi Mahmoud, I did try that “fix” from MS and it didn’t help. I even tried uninstalling the fix and reinstalling it. Vista still exhibits the same behaviour.

  13. Ahhh ok. Thanks Mahmoud. I hope this problem gets resolved for everyone soon. I’d like to think of Vista as being a serious platform for graphics work, but this is a major problem for anyone trying to create professional output, and it’s discouraging that it’s still not fixed for many people. Anyway, hopefully our discussion here will help others who are looking for solutions to this…

  14. Likewise here, still the same behaviour in both 32 and 64-bit flavours of Vista with the patch mentioned by Mahmoud. The problem could be in two areas, one in Vista and two the graphics driver knowing what custom LUT was loaded via a third party so that it knows to restore that value on card reset.

    Shame the problem has been un-addressed for so long.

  15. I’m currently on Windows XP x64 now, but previously I was on Windows Vista x64 (as stated in my earlier comments) and had the issues thankfully resolved through one or more of the updates to Vista post-SP1.

    I’ll send an email to some guys at Microsoft and see if they have any advice to offer, but don’t held your breath.

  16. It occurred to me that one way to get MS’s attention is to comment on their advisory, that Mahmoud posted earlier:

    If enough people click on “No” under “Did this article solve your problem?” and describe what’s happening for them, then Microsoft’s knowledgebase software will flag this issue for review. So, if you’re having this gamma table bug issue still, please take the time to do this.


    Add a link to “” in the description, it’ll show them you know what you’re talking about.

  17. I also just noticed that the update was meant to resolve this problem for people with multiple-monitors… does everyone here experiencing this issue have multiple monitors?

    I personally do (and this update fixed it), but I’m wondering if perhaps there is another bug for people w/out multiple monitors that is causing this problem to persist and going undetected since it’s actually a different bug than the one solved with this update..

  18. Very good point, Mahmoud. I did notice that yesterday too. I only have one monitor. Maybe the problem could be fixed by buying a second monitor? 😛 Anyway, an interesting note for sure… I don’t see a related bug listed in MS’s knowledgebase. I’ll report in the comments on the issue that I only have one monitor, and, as you noted, reference this thread too.

  19. Hi guys, i do not know if my problem is the same as yours. I am running on a vaio laptop and recently upon updates from microsoft’s auto updates, each time my laptop sleeps or hibernates, the screen would be so bright that it looks like its covered 95% in was still functional except that the display was amazingly too bright to navigate. The situation was ok after i restarted or avoided letting the laptop sleep. But suprisingly, the situation becomes permanent and each time i start windows, the display would be super bright as always. I have tried putting the gamma, brightness etc in nvidia control panel to the lowest.. but it is still bright. I have not yet tried formating but i do not have any intentions as yet. I did tried system restore to earlier dates but still the problem is not solved. It’s been about 4 days now and its a depressing state lol. I would deeply appreciate it if there is anyone here who have any idea what went wrong. still, if my problem is the same as the previous entries.. i would just wait for updates. THANKS!

  20. ICC Profiles override gamma settings on the monitor and graphics card – there is a good chance that you’re seeing the same issue as others in this thread.

    Update all graphics drivers & install the patch all the while praying it’ll work and see what happens 🙂

  21. Thanks for the advice man. Its strange because now the screen flickered then the screen magically went back to normal. But after i install updates due to system restore, the screen went bright again. Its strange that the updates was important and recommended updates that are of security and vista’s update files. I once again system restored back and after few moments surfing IE in the awkwardly bright lighting, the screen went back normal. Now im trying to update without an optional driver update for my graphic card. Hope everything will be fine soon

  22. Strange one, I’ve only just bought a new Sony Vaio FW series laptop (Vista Home Premium), installed all the usual stuff I use (Full Office 2007, CS3, Lightroom, Nikon Capture NX, DevStudio 2008) and Huey Pro and found I don’t have the same LUT problem as I did with an N-series using integrated Intel 945GM graphics. The new laptop is using a dedicated ATI graphics controller. After nearly 2 years I’m starting to think that the problem now lies more with the graphics drivers (Sony with built in Intel controllers have been poorly supported with compatible updates).

  23. Maybe the ‘bug’ is in MS’s WHQL testing (or whatever they use these days), which doesn’t verify the drivers work in this respect?

  24. The fix Microsoft implemented is more of a workaround. Some activities still may cause the LUT problem. However, it seems that now windows vista has a service that checks the profile on an interval. If this supposed service sees the profile in the LUT differs from what is set it switches it back automatically. You can test this by setting the correct profile, then putting your computer to sleep. Then wake it up and you should see the wrong profile. Wait a few minutes and the right profile should be set automatically. At least this is how mine works.

  25. I am running Vista Business 32 bit in bootcamp on a Mac and also have the problem. I have fully calibrated my external monitor but when Vista starts it always selects the sRGB default profile. I have to manually call up my calibrated profile. I have installed all updates which include the security update referenced by Mahmoud. Very unfortunate that Microsoft doesn’t provide a permanent fix for this bug.

  26. Hi Drew, do you know what this service is called? I was hoping it would work for me, but it doesn’t. I waited about 10-15 minutes after waking the computer, and the profile did not switch by itself. Maybe the service isn’t running on my computer? Anyway, it seems like a bit of a half-hearted fix. If there is a service that fixes the post-sleep profile problem, it should be set to run immediately after waking the computer.

  27. A couple days ago I fixed (on my comp) the “waking” and other problems by unchecking three Intel Common User Interface modules in System Configuration/Startup menu. Since then – no problem. Just don’t touch any related to graphic adapter menues. (Vista Business 32, HP Compaq 6530b).

  28. An alternative to displayprofile is Xcalib – it’s originally for linux. Basically, you can have it set an icc profile as well as alter the gamma by passing it arguments (it’s all command line). I’ve got a shortcut set up on my desktop so I can just double-click and switch the gamma back.

    Just put something like

    C:\YourPathHere\xcalib.exe gammaadjustedprofile.icc

    in the “Target” field of the shortcut.

  29. MS considers this to be fixed, according to their fix listed here:

    If it’s not working for you, let MS know by commenting at the bottom of the knowledgebase article. Hopefully they’ll get the hint and have another look at it. Until then, check out the XCalib/Hibernate Trigger solution I posted above. It’s working perfectly for me right now.

  30. It seems like problem is not in Vista but in video drivers.
    I found a solution for my HP 2710p (intel 965 video)
    by removing igfxpers.exe from autorun.
    It’s important to leave alone igfxtray.exe and hkcmd.exe
    or trick will not work.
    On my desktop pc i have no problem with Radeon 4850 as it is.
    I use BasICColor Display and Spyder 3.
    Windows Vista Business SP1.
    Windows Vista Ultimate SP1.
    Good luck 2 everyone 🙂

  31. I have a Intel X3100 based X61 tablet, and I tried the trick of disabling igfxtray.exe from startup, and that seems to have fixed my problem. I believe this is some sort of bug or conflict with the Intel driver’s color management features.

  32. thank you, killing igfxpers.exe fixed the problem on my lg-r510 with intel 4500mhd video.


  33. The problem is with Vista and it is well known bug in the system. Vista keeps on resetting callibrated colour profiles to WCM each time you reboot etc
    John D

  34. I don’t know how you have come to the conclusion that it is not Vista when Microsoft admit there is a compatability problem as does X-rite (Eye-One Displaty 2) monotor profiling device/software.
    GOOGLE is full of the problem from many web sites etc.

    John D

  35. Matt, are you serious? :S

    One would have hoped that since it’s really obvious that MS has discovered the cause of the bug, it would’ve been vanquished in Windows 7…. :'(

  36. Yep! The bug is back in Windows 7 – this annoying thing is still their. I “love” Microsoft – they can improve your shitty “Virus Defender”, make their buggy ReadyBoost crap, create their Surface for CEO’s fun – but they never fix the really annoying bugs with end-users experience issues immediately. You have to wait for dozens of years.

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