Got off from work and decided to grill a hamburger on my grill in the back yard..it was around 2330 hours when I caught a glimpse of an unusually bright green ball of light.I thought it was a helicopter but as it headed in a southern direction towards me it stopped turned red then back to green.It went left then right ,made a quick ascent upwards then came back down and hovered.It changed to a row of white lights then back to a green then bluish then a red glow.It looked disc shaped from what I could tell in the darkness.The object was about 300 to 500 feet away but I could clearly see it and watched it for about 3 minutes or so.It stayed around the same area hovering and moving left and right then it moved in an easterly direction and went out of my sight as my house roof blocked my view.I went to the front yard and saw it pass over a tree line and then disappear. Within a couple of minutes I heard a helicopter coming from the south and saw its yellow white light and it passed to the east like it was looking for something.It then hovered for many minutes to the east of me about half a mile away before going back the way it came.The ball of light I saw was no helicopter or airplane.I guess it could have been some sort of hovering drone but it seemed large and cannot understand who would fly such a thing that late at night.