and and one from their father, which get passed from generation to generation.... all babies get genes from their parents, who in turn got genes from their parents... -all- of your genes came from your parents, if your parents don't have the gene, you can't get it. (unless you're a mutant)
Hair and skin color are complicated because there are lots of different genes that control it, which is why we have so many shades of colors of hair and skin color. But the Rh factor is simple, just two options + or -. If you are Rh-, then you are - - (one negative came from mom and one from dad). If you are Rh+, then you are either + + or + - (it only takes one positive to make you positive)
If both parents are Rh+ and have mixed genes (+ -), then it is possible that each of them will give the - gene to their child, making the child Rh- (- -). (there is a 25% chance that the child will be Rh- and 75% chance that the child will get a positive from either one or both parents)
If one parent is Rh+ and has 2 positive genes (+ +) then it doesn't matter what the other parent is, all the children will be Rh+ Here is another website that may be able to help ans some quest: http://www.thetech.org/genetics/ask.php?id=114
So, to answer your question. Two Rh+ parents can have an Rh- child..... but the negative still came from the parents.