I use here three spot lights, each different color: red, green and blue. The result in MuPAD is not the best. I would expect much stronger spots of lights, this is reflection from a white surface.
Image obtained in MuPAD using spot lights.
The same model with default in JavaView spot light parameters.
The same model with some improvements: radius 15 deg and corona 30.
The same model with some improvements - radius 0 and corona 75. All three lights are fixed to the camera location.
The same model with some improvements - radius 25 and corona 5 + highlight on.