Most CCD cameras are monochromatic, meaning they just record the intensity of light and then display it in shades of grey running from black ("no light", underexposed) to white ("too much light", overexposed, saturated).In order to get color, one would place a filter in front of the chip so only that color of light is detected. The image is still monochromatic, but if you combine that image with images taken through other filters, you can produce a color image. What filters to use? This depends ultimately on your goals. Do you just want a "pretty" color picture or are you trying to image emissions of certain gasses at certain wavelengths?