At what point is it appropriate to use a single icon space to represent the current state of something, and when is it appropriate to use several icon spaces (one for each possible status) with the one representing the current status being the one that is "on."
Example (active status):
Status: (red - OFF) (yellow - OFF) (green - ON) (white - OFF)
My initial thought is to use a single icon space for items in a list or table format, while using the multiple space format for something like overall application status. It adds some distinction between the two types of status, but other than that I can't really see why I shouldn't just use the single icon space for both, since it is simpler and easy to interpret.
I'm looking for pros and cons of both approaches, and if there is a standard I failed to find that already addresses the question. Please assume that in both cases there would be hover text or some other form of textual information that further describes the status. I'm not looking for the metaphor to use - it's more about the arrangement of the metaphor.