The standard Image Viewer shows other colors than Blender or GIMP on many images.
Also Chrome has this issue, but Firefox is fine.
Further more, there is a similar but different problem with the standard Video player, I always had to watch the video in Chrome (which shows correct color for videos).
It’s most likely the image colour space is not correctly interpreted.
Blender assumes you want the image as sRGB but does not assign a colour space when you save the render. This leaves you open to each application interpreting the colour space however it ‘wants’.
To ensure images are interpreted the way you would like, open it in an image editor and assign an sRGB colour space profile.
In Gimp 2.9 it is Image -> Colour Management -> Assign Colour Profile.
Firefox will assume sRGB for any untagged image. The ‘Image Viewer’ may not be colour managed at all, depending on which one you are using. I believe EOG will interpret correctly if a colour space is assigned, but Mate Image Viewer is not colour managed, last time I checked. I don’t know how Chrome manages colour. I’m guessing it makes no assumptions and has to be told.
Anyway; short answer - assign a good quality sRGB colour profile.
Not sure what you mean by biggest. Assuming you’re exporting 8bit files for web use I would recommend to first assign an sRGB profile so that the web browser will display the data as intended.
LargeRGB, if that’s what you’re using, is not the same as sRGB and if assigned will probably cause a colour shift. You can convert from sRGB to something else later if you need to.
Elle Stone says the sRGB-elle-V4-srgbtrc.icc profile is the same as the Gimp’s built in sRGB profile. It should be ideal for web use.
EDIT - Of course if you’re starting from an .exr you can use one of the linear profiles, and convert to sRGB for web use.
The color profile assigned (in GIMP 2.8.16: Image > Mode > Assign Color Profile) images look good on my computer but they are still wrong on a different computer.
I just meant the different data the viewer apps produce.
Why is Chrome producing different data, if both don’t know the color profile they could have used some standards. I don’t see differences on Windows for example and nothing is calibrated or set up manually.
Images in which file format, viewed in which software application?
Is the software colour managed and using the monitor profile?
So, is this on one computer or two?
Are they both using the same monitor?
For two monitors to display the same data the same way, they need to be colour managed. For different applications to display the same data the same way, they need to be colour managed.
In a colour managed browser a correctly tagged image will be displayed correctly. You need to ensure the image is correctly tagged, and that the browser is colour managed. Then the monitor needs to be profiled to display the data the same way as another profiled monitor.
I’m afraid you have entered a world of pain, but it is very rewarding once you are aware of how to handle the issues that may come up.
The V2 profile may be a little old now. Perhaps try again with the V4. This site has some test images you can use and will walk you through checking colour management is on for Firefox:- http://www.gballard.net/firefox/#config
I don’t have Chrome to test with, but I would trust Firefox to get it right more than Chrome. Some simple image viewing applications may not be colour managed at all. Windows is a different environment again with the same issues.