I’ve used this desktop background for years! Over at http://www.hutchcolor.com/Images_and_targets.html, they’ve given public access to download many of their print-specific and monitor calibration-specific targets, images and tools.
One that is a standout is their desktop background, called “CMS 30 128.JPG” (36 K – RGB) (I cannot simply provide a link to the image download due to their own restrictions [which I honor], so go to the link above and get it!)
It looks like this (but is not this – go download it at the above link):
Install it as a desktop background and “tile” it, and it will provide a perfect, even gray, non-distracting background for your color editing work in Photoshop.
HutchColor is a family run business by the Hutcheson family. Check out all their Free and Cool featured stuff, of course, but please do take notice of the great Services and Tools they have that keep their business such a vital service to the printing and imaging industries.
I have no affiliation with them – those links are not affiliate links. I just think this company rocks and has done so for a long time. They’ve been doing this stuff for us for years, so kudos to them!