NEC LT35 color problem

If you're trying to project video, then the unit needs professional service. If you're trying to project from a computer, you may have a loose display cable, broken pins in one or both ends of the display cable, or broken conductors (wires) within the display cable. The computer sends its image information as a template of RED image components, GREEN image components and BLUE image components with the projector overlays to create the complete image with blended color values. (The computer also sends HORIZONTAL and VERTICAL synchronization signals, but those don'e affect the color content of the projected image.) That's why I'm suspicious of the display cable, conductors or pins.