fasterem: Seeing as you are only getting black and white pictures, could you set the camera up in the open, but not facing into the rising or setting sun. If this is possible, then walk toward it or whatever to cause it to trigger. After a few tests like this you could then return it to where you had it set up. Then just swap out the test card to see what is happening. You wouldn't have to move the solar panel, just test using batteries. If the camera still just takes black and white pictures, then you will know whether its a faulty camera. Also see if its a sunny or cloudy day when you do the tests.
If you have to send the camera back, include a note of what the camera was doing, how and where it was set up, type and strength of batteries and maybe include a few pictures. This would be a great help to the technician that services your camera. Hope this helps.