Currently, Blender always uses the scene's display and view transforms
when saving images through the Save Image operator or the File Output node.
With this commit, settings are exposed in the image format panel that
can be used to select a different display, view, look, exposure etc.
The code was already pretty much there since 2012 but was left disabled.
@Sergey Sharybin (sergey), is there any issue that caused you to keep it disabled?
The only downside I can see is that if a user adds a File Output node
and then changes the scene settings, the node will no longer mirror these
changes. Maybe adding a checkbox "Use custom color management" would help?