Q: Bootcamp Update 3.1 on Windows 7 screws up my color depth!!

You should post your question in the Boot Camp forums:

http://discussions.apple.com/category.jspa?categoryID=237

Try installing an updated video card driver in Windows.

I just installed the latest boot camp update and it messed up my colors, too. So - I installed an updated driver for my video card through the Windows Control Panel Device Manager and that did the trick -- it automatically reset the colors to the correct depth while installing the updated driver.

Sorry - I spoke too soon. The driver update apppeared to fix it but then it reverted. Color still an issue.

I to had this problem as well. I just rolled back my video card driver and it seemed for now to fix the problem. Good Luck! hope it works for you.

Hmmm.. roll back to what? I have only installed the drivers provided with boot camp. I semm to have two options: Correct color depth - wrong resolution. Or correct resolution, wrong colordepth

After installing boot camp 3.1 on the 27" iMac I noticed that the color dept was off. The computer was clearly being displayed in 16 bit mode. Although it said 32 bit I wasn't convinced. At that point I went and used the roll back driver feature for my video card. It seams that boot camp 3.1 updates the video card to a newly better suported video driver but that don't seem to be the case. This might only apply for the 27" iMac I can't verify this to work on other models. If your unsure on how to roll back a driver write me back and I will give detailed information on how to do it. Good luck!

How can I install ATI's driver, NOT Apples version for boot camp? I'm new to Mac and regretting my decision as it seems like every "fix" they come out with just ends up breaking something that wasn't broken.

I'm having the same issue. I spoke to Microsoft and AMD. It's not a Microsoft issue. It may very well be a driver issue. AMD's ATI drivers are being written as OEM by Apple, so AMD doesn't provide the specific drivers for the ATI Radeon 4850 - instead they should come through Bootcamp.

I have used Bootcamp 3.0 and 3.1 and both have issues with banded gradients and the 16-bit color appearance. I'm not 100% sure it is 16-bit or just looks bad. When I turned on 16-bit colors in Windows, it did look worse. But it's definitely not normal 32-bit color depth.

System Info:
iMac 30"
OS X 10.6
Windows 7 32-bit
Bootcamp 3.1
ATI Radeon 4850

please teach me how can i roll back that driver.. i have had the same problem here in my imac 27..

I rolled back to

9/23/2009
8.661.0.0

and it works better. You can immediately tell the problem on the standard windows logo background. This is the driver that was pushed to me from windows update prior to even installing boot camp 3.0.

The driver that 3.1 pushes is

8.861.0.0
11/24/2009

and it does set it to 16bit color even though if you list all modes and select 32 bit color it doesn't change anything.

to rollback the driver, right click on my computer, select properties, select device manager, expand display adapters, select ati radeon hd 4850, right click, properties, select driver tab, select roll back driver.

Same Issue here, it got resolved after rolling back.

I only noticed that my iMAC heats when using windows and the fan works non-stop. but when using MacOS it never happens??

I found the following discussion very useful. Rolling back to the 8.661 driver fixed the 16-bit color banding for me!! Hopefully this driver has no other problems.

Screen resolution > Advanced Settings > Properties > Driver tab >
Update driver > Browse > Let me pick > (find 8.661)

http://forums.macrumors.com/showthread.php?t=843992