The Orange box is the one that is referred to as 'scan for file additions and updates'. These need to be ticked if you want Serviio to register any new, updated (see red box) or removed files in those folders. No new files (after the initial scan) will be added to or removed from the library if this box is not checked.
The Green box is the section that make Serviio update the library all on its own 'automatic update'. If you untick this box the library won't update till you click 'Force refresh' button. Serviio only checks for new additions/updates in folders that have this feature enabled (see orange box).
The Red box is the one that makes Serviio monitor the files currently in your share folders and changes them as you do (e.g. editing ID3 tags in mp3 files, adding folder.jpg album art file, updating XBMC .nfo file, etc.). Serviio only checks for file updates in folders that have 'scan for file additions and updates' feature enabled (see orange box).
Green dot means Serviio detect that the device is on or active (with Upnp respond to a search detection mechanism) and automatically select the proper profile (if a specific profile exist).
Red dot means Serviio doesn't detect the device after an Upnp search mechanism (that supports this feature)- Means that the device is off or inactive.
Orange dot means Serviio doesn't know if the device is on or off at that moment - Means that the device doesn't support Upnp search mechanism.