I, and another individual, observed a triangular-shaped, multi-colored, silent object slowly traverse the night sky of New Haven, Conn.

I was a graduate student attending Yale University. I was lounging on the roof of one of the University buildings (located in the heart of downtown New Haven) in the company of 2 other students. One student was about 30 feet away and was standing near the edge of the roof and was looking down at the street. I was lying on my back looking at the beautiful clear summer night sky. The other student, a friend named ((name deleted)), was crouched next to me and was talking to me. 
As I looked at the stars I suddenly noticed, coming into view, a triangular-shaped object moving rather slowly, and very smoothly, across my field of vision. It had rounded edges, made no noise I could hear, and had solid, regularly spaced bands of various colors which slowly passed across it's glowing, illuminated surface. I was stunned, and remember thinking "What the hell is that?" 
After a few minutes it faded from view, and I realized that I had just seen a UFO. At this point I had said nothing, and ((name deleted)) was still jabbering away to me about whatever. 
A minute or two later the same object, or a second, identical object, traversed the night sky above me, but in a different direction (I do not recall N/S/E/W details). This time I said to ((name deleted)) "Hey! Look up there and tell me if you see that?"   He looked up and exclaimed (and I remember thinking this was funny) "What the hell is that?"   
I can't judge the size of the object because there was nothing available to apply scale, but I had the "feeling" it was something quite large and several hundred yards above.  I think I got this sensation because of how stately it moved across the sky; absolutely smooth, straight, and rather slowly. 
To this day I am grateful the damned thing gave me a second chance to get ((name deleted)) attention. If no one else had seen it I might think it was just my imagination. 
I don't know what it was, but it absolutely was not a planet or a star, nor a prop-aircraft, a jet, a copter, a kite, a satellite, nor do I think it was a blimp (although I suppose this is a remote possibility, but it would it have to have been one helluva weird blimp).
Witness indicates that date of sighting is approximate.  PD