Blue-purple Spherical object seen in Manhattan, NY

A spherical object was moving outside my window at a speed 10 times slower than an aircraft, then stopped moving. It had three layers of color. The inside was dark, the middle was royal purple, and the outside was bright blue, similar to copper chloride when burned. It was still moving, but at a speed so slow, similar to that of the moon, that it didn't appear to be moving. It could have been a satellite or star, but its behavior was unusual because it was moving about 2 inches in my view, then stopped all of a sudden. I did not hear anything because the city is loud and my windows were closed. I was wearing glasses when seeing the object.