Mystery colour problem

@adambarnes2011 as others have written, for accurate colour across your system you must have properly calibrated & profiled displays. I also agree with Dave that a visual calibration tool is quite a flawed way of achieving this. Because the result is very unlikely to be correct.

To check calibrated & profiled appearance I use this:

Have you ever wondered how to KNOW whether your screen [or printer] is ACCURATE and not just 'pleasing'?
If so please check this out: http://www.colourmanagement.net/products/icc-profile-verification-kit

I hope this helps
neil barstow, colourmanagement net - adobe forum volunteer - co-author: 'getting colour right'
google me "neil barstow colourmanagement" for lots of free articles on colour management

I've moved this thread from bugs to discussions as it is not a bug.

Dave

No mystery.

Photoshop uses the monitor profile it gets from the operating system for each screen. When you drag, the profile is switched at the instant you drop anywhere over the mid-line.

If colors are wrong, your monitor profiles are no good, or one is good and the other wrong.

To get them both correct and matching, you need to use a calibrator to make a monitor profile for each screen. To get a good match, both screens should also be calibrated to a visually matching white point.

The monitor profile is a standard icc profile just like e.g. sRGB or Adobe RGB, only custom made by measuring the screen with a colorimeter. Photoshop will then convert, on the fly, as you work, from the document profile and into the monitor profile, and those numbers are sent to screen.

(EDIT cross-post)

Photoshop is colour managed. That means it uses the colour profile for your monitor which is set in the windows operating system to translate the color values in the document to the values needed by the screen to display the document correctly. That happens in the background without you doing anything.

When you drag a window onto a second monitor screen you may see a point at which the profile being used switches from the first monitor to the second.

To display colours accurately it is essential that each monitor has a profile that describes its behaviour with its current settings. This is normally made with a calibration tool such as the i1Display or similar. The profile for monitor A will be different to the profile for monitor B so each monitor should be separately profiled. Photoshop will then use the appropriate profile for the display being used.

If you have calibrated and profiled your monitors the only difference you still might see is where one monitor has a wider gamut than the other (in other words it can display a wider range of colours). In that circumstance a particular colour might change simply because it cannot be displayed on one of the monitors but can be displayed on the other.

So start with your monitor profiles. Have you made a profile for each, in their current state of adjustment? Changing a monitor adjustment invalidates the profile so a new profile must be made.

Dave