Whatever you decide, remember how your kit will be seen. Primarily that is in photos an at public events. You want something that has nice visual contrast so people can "read" your costume. The danger of navy blue and black is that the whole ensemble comes across as very dark and people might have a hard time seeing all the hard work you put into your armor. If you go that route, I would advise finding ways to add light colors or highlights.
Personally, I think the green would look best, because it naturally lends itself to variations. different shades of red can clash, but with green they tend to look more like camouflage. You can have elements that are dark green, light green, pale green, olive, etc. It adds more visual interest and, as others have said, it is a little less common than red and black.
