This is a time-lapse clip taken from footage shot 29 April, 2012.
The aircraft crosses the frame from right to left with a bright white flash every 9 to 12 frames.
As it flashes close to the City, it flashes a blue flash with a center point and four perimeter points.
Then, the last flash before out of frame is white again, with maybe a slight reddish tint.
Take a look and see if you can identify the craft that does this...