OCIO configuration files allow for the use of contexts, which are essentially environment variables that refer to color transform files. Contexts can be used to facilitate per-shot color grading, for example.
If you are using OCIO contexts, you can change their value during a session without restarting Maya. To do this, use MEL or Python commands to change the environment variable and then refresh the color management preferences.
putenv "SHOT" "ijk456.spi1d"; colorManagementPrefs -refresh;