Color printing question

[jyl]

I need help understanding the color wheel. I took a class in color printing and simply could not "get" the relationship between the colors and how you correct color problems. The instructor did her best but I just couldn't grasp it. Can anyone help?

For example, suppose I print an image of a sports car that is supposed to be Ferrari red, but my print comes out orange-y. What should I do and more importantly why? Suppose I print a picture of my daughter and her face comes out greenish. Same question.

I am also having a lot of trouble photographing in color, as I think I see eveything in balck and white - but let's leave that problem for later.