In SALOME you can set preferences for each module in the common editor of preferences. SALOME preferences refer to the whole GUI SALOME session, others are module-specific and are accessible only after you load a respective module. When you change settings (click “OK” or "Apply" button) each module receives notification about what preferences are changed. The preferences, set during the current study session, are automatically saved in a special user file at the end of the session. So, next time you launch SALOME application, these preferences will be restored.
The preferences you set will be default preferences for all new objects, but they are not retroactive and do not automatically apply to the existing objects.