I dont know myself exactly, but you can talk to this guy on yahoo. ankit_jain_gzb or you can mail him on ankit_jain_gzb@yahoo.co.in

Well for a start to make an ellipse appear like a ball you need to make a CIRCLE not an ellipse, then depending on the angle of the light you need to do some VERY basic lighting algorithms ASSUMING the object IS 3 dimensional. If you set the light source to be pointing through the centre of the circle and its angle varying as it travels around the shape then the lighting shouldnt be too hard to figure out. What output do you have at the moment?

Sorry I re-read the question. Your instructor is asking you to do a 'fake 3d' lighting effect (I was going to show you a 'real' techniqe!). He / She has said that colour must fade depending on distance from a point. So here's my solution

Process WM_LBUTTONDOWN messages so that wherever you click this is where the light source is

Loop through the 'ellipse'. Using pythagorus' theorum you can work out the distance from the current shape pixel to the light source pixel (where the user clicked) then by scaling colour components by this value you will get RGB values required at each pixel and therefore have done the fake lighting tech!