Brenda,
You are correct to presume that a displayed red light does not always mean danger, nor does a green light imply safe harbor/passage. There is much more that goes into the decision as to what color may be displayed, as John noted earlier.
The Coast Guard maintains a listing of all navigational aids (not just lighthouses). The list is published in books specific to a certain area of coastline or waterway. Each aid will be listed, along with its specifics such as description, flash pattern, light color and anything else that will help a mariner identify the aid. A
Local Notice to Mariners is published periodically to notify mariners of updates, changes, deletions, temporary re-positioning or outage and such. Here is an
example of a light list from our Canadian neighbors, eh. Pick a region and open the file (you will need Acrobat Reader). The first file is all the details of what is being said in the lists.
This page has some interesting info on aids to navigation, again courtesy of the Canadians.
Even though these examples are from Canada, the information is going to be very similar to what happens in the US. The light lists will pretty much follow a standard layout everywhere. In the US, the list is maintained by NOAA and is not published on the internet (according to what I read on the USCG's site someplace).
Anyway, these sites ought to give you something to increase your knowledge! Have fun,
Dave
[This message has been edited by Dave H (edited 02-18-2002).]
Bob