Try a different VGA cable.
+1, the different colour information is sent on different pins and the most common cause is when the cable is stretched and one of the colour pins is disconnected, rendering everything in a different colour. This especially happens with the bargain basement VGA cables that aren't always soldered together brilliantly.
I'd also try swapping the splitter outputs around, it's possible that there's an open circuit in the splitter somewhere causing the same sort of issue. Unlikely, but since it's an easy test it's worth checking.
Beyond that, you're looking at something wrong inside the projector itself, perhaps a dry solder joint, damaged lamp or something else. Whatever it is though if things have gone that far then I'd suggest waiting for the tech in the know to come and sort it out