I have just built a new PC and re-installed my Adobe CS4 Master Collection. When I first opened Photoshop, the default white background was a Yellow colour. Eventually I worked out that it was to do with colour profiles and selected a profile associated with my monitor (Samsung Natural Color Pro 1.0 ICM). This turned the Yellow back to white and all was good. Now I am trying to edit some product photography sent by a supplier and though the images look fine in the windows thumbnail, when I load it into PS, the white background of the image is yellow. On closer inspection, if I preview the original files in Windows, I see the Yellow backgrounds. The Yellow background also stays if I save the file and then will show on the thumbnail as yellow.
I'm lost. Can anyone help or show me to a guide or how-to please?
white appears yellow in Photoshop is a sure sign your OS default monitor profile is off
Windows default monitor profile is set in Control Panels> Color Management> Devices tab> check Use my settings for this device> set your custom monitor profile "(default)" as pictured in screenshot:
but i hope you don't mean you selected your monitor profile in Edit> Color Settings> Working Spaces> RGB: monitor profile -- that should be sRGB (as a start like this, with these Color Management Policies in place):
that will help ensure you are using the correct Source Profile on your documents and warn you of missing profiles and profile mismatches
IN OTHER WORDS
you need to 'calibrate' a good monitor profile
get it set as the Default in Windows
and configure Photoshop Color Settings to use the correct profiles (or warn you of problems that could be causing some of the problems you describe)...