Confused by colour management

[Philip Goh]

I've been trying to wrap my head around colour management, and I've found the series of articles here to be helpful. However I'm still concerned that I'm doing something wrong!

I have a Spyder2 colorimeter and I've calibrated my monitor with it. It's generated a colour profile called "Spyder2Express.icm" which I've applied via the Control Panel in Windows 7 and I've noticed a distinct change in the way things are rendered. Everything appears "warmer" and slightly more contrasty, blacks are closer to true black. So far so good.

Now in my favorite image manager (Bibble), I enable colour management and set the monitor profile to the "Spyder2Express.icm" file, everything starts to look slightly strange. I find posterization and colours start to band. If I set the monitor profile to sRGB, then things start to look normal. My interpretation of this is that the application is applying the colour profile twice and is thus screwing up the colours. However, this is not limited to Bibble. I've tried IrfanView and Gimp, and when these applications automatically detect the screen profile, I get the same funky colours I'm seeing in Bibble.

Am I doing something wrong?

[Philip Goh]

To help, I'm attaching screenshots of what I see when I have the bog standard sRGB profile versus the generated Spyder2Express.icm profile.

Calibrated screenshot. Notice how the apple red's look angry and have turned into one undiscernible patch? There's also a yellow tint to the overall image.


Bog Standard sRGB. The apple red's are more subtle and you can make out features on them. No yellow tint. The patch of blue on the top right actually looks blue instead of purple, which is closer to the scene's actual colour.

[Philip Goh]

I finally figured out what was going wrong. I had switchable graphics enabled, where the laptop would use the discrete graphics chip when plugged in and the integrated graphics chip when on battery power. Whenever a switch occurs, it screws up the colour management and things start to look weird.

To fix this, I disabled switchable graphics in the BIOS and I'm now always on the discrete graphics chip. This hasn't been too bad for me in terms of powermanagement. The reported battery life has gone down from 9 hours to 8 hours, so the battery life hit wasn't as bad as I had anticipated.

[Colin Southern]

Hi Philip,

Something still doesn't quite add up here. Normally one would tell the operating system to use the display profile -- I can't see what use any application would have for it.

[Philip Goh]

I know it sounds like the colour profile is being applied twice, but I've been repeatedly assured by various people (some of whom have written graphics packages) that this is correct. My understanding of this is as follows: The operating system loads the monitor profile and sets up the graphic card to render colours in a certain way. Next, you need to load the monitor profile in a colour management aware graphics package so that the software knows about the characteristics of the screen.

I'm happy to be proven wrong, but I remember coming across an Adobe KBA regarding colour management in Photoshop and this is what they suggested.