You are probably seeing the effects of chromatic aberration. Bluer colors get refracted more strongly than redder color. The thing that makes it look 3d is that

You are probably seeing the effects of chromatic aberration. Bluer colors get refracted more strongly than redder color. The thing that makes it look 3d is that this effect is more pronounced the further from the center of the lens you are looking. So in your left eye for example the yellow boxes are closer to the center of the lens than in your right eye, the chromatic aberration will shift those yellow boxes more in your right eye relative to how the blue background gets shifted, and that results in what your brain perceived as parallax which makes you think the image is 3D.