You will probably find that the students spend a lot of time agonizing over the accuracy of their calculations. You can't really recognize anything with only 100, 4km pixels. This tedious work explains why we use computers to process satellite images and also why satellite remote sensing was not really possible before the advent of computers. Color blindness is a general term for a deficiency in the visual system that leads to a distorted color perception. Speaking very loosely, we have three types of color receptors in our eyes, sensitive to red, green and blue.
Color blindness comes as a result of a lack of one or more of the types of color receptors.
The best I can do is to try to describe effects. If a red-green color blind person sees a red object and a green object which are about equally bright, the red object will seem much darker than the green one. This person will find the display of an old LED calculator almost unreadable A good approximation to the world of a color blind person can be obtained by unplugging the red cable from a graphics display. And it is possible to have the color receptors missing entirely, which would indeed result in somebody having monochrome vision.