When you add an image to a color-managed scene, you need to specify the color space used by the image so that the colors can be properly converted to the working space used for rendering.
New File textures and image plane nodes in the scene initially use the color space determined by the Input Color Space Rules in the Color Management preferences (see Define rules to assign color spaces for input files). However, you can change each node individually by manually setting Color Space in its attributes.
Once an input color space has been assigned, it does not change unless you change it manually or reapply the color space input rules to the whole scene (see Change existing input color spaces automatically by reapplying rules).
However, wider-gamut spaces are becoming increasingly used.