Marcin Zieliński writes:
If you use Mac or another system with color calibrated monitor, you've probably noticed that your renders do not look the same in Blender as in other programs. To simplify things, your monitor might display colors outside of the srgb space. E.g. if we assume that red can be stored in values 0 to 1, 0.8 red of your monitor might look like maximum red of srgb. This offset is decided by the ICC profile used in your system which in layman's terms is a curve telling how far your screen colors differ from RGB gamut.
Unfortunately, Blender does not handle color profiles, so it has no way of knowing that. It will output 0.8 srgb red not knowing that it looks like 1.0 srgb red on your screen. Then, when your saved render is opened in other color managed applications that think they are dealing with an srgb image, what you thought to be 1.0 red becomes 0.8 again... The simplest remedy to this problem is embedding your monitor ICC color profile into your render, so other applications know what that 0.8 red should look like on your screen. That can be done in Photoshop and other application, though I would like to present to you the easiest way to do this using only Blender and Styriam ICC Image Compressor addon.
First, install PIL and select your monitor's ICC profile in the addon preferences, then just embed it when saving the file. Done.
In the image editor, instead of the standard "Save As..." select the new "Save As... (advanced)", and then check the option to use a color profile.
With this addon it is also possible to convert from your monitor color space to your desired color space, which is probably the sRGB. In this case, find sRGB color profile in your system and select it as the output color profile. Then, choose option to convert color space when saving the file.
This solution will unify how your renders look across other application, however it will not solve other problems. Images and textures imported to Blender will still look incorrectly, so keep that in mind in color critical applications.
As a side note, this addon also lets you efficiently compress pngs and jpegs and generate nice looking gifs but this will be covered in another article.