This could be due to the fluorescent lighting and high shutter speeds. Fluorescent lighting cycles can be caught using faster shutter speeds which will give strange bands / patterns and color shifts.
Try keeping your shutter speed below 1/60 and you should be fine.
PS: If you do not notice anything like this while shooting in the daylight, there is nothing wrong with the camera.
1DX, 5D3, 600D, RX100
16-35L, 24-70L II, 70-200L II, 100-400L, 50L, 85L II, 135L, 24TSE, 40, 100 macro, 18-55 II, 55-250 II, 1.4x III, 2x III, 600RT x 4
The grass is always greener when you crank up the saturation in photoshop