I know that green edging strips are used on bag tags for flights originating in the EU. Some (but not all) of the tags on bags I've checked in Malaysia have had orange edging - what does that signify? I've also seen tags with red edges - what does that signify? And are any other colors used?
I assume that you are talking about bag tags for checked baggage that are printed when you check the baggage.
Those tags are specified by the IATA in their Passenger Services Conference Resoultions Manual (unfortunately there is no official/legal download link for the whole thing, as IATA charges $750 for it).
I was only able to check the 2010/2011 version, and in general those tags have to be white with black printing. Expedite tags may have red "hatching" on the border, but this is optional (black can also be used for the hatching). EU bag tags have the green border.
As far as I have seen no other colors are allowed on the bag tag itself, although there may be additional stickers ("expedite", "first class", etc.)
Green on Handluggage is guarenteed in the cabin because it fits under the chair infront of you.
Red label are not guarenteed in Cabin. As a flight is full and very busy you're luggage may be moved and have to be picked up as normal suitcase at the airport.
I always make sure when boarding begins i am one of the first 50 person to go in the airplane. They stop you if you are one off the last to enter and the plane is full with handluggage.