What is symbolic about Jonas' and the Newchild's eyes?

Everyone in Jonas' community is the same. They have the same experiences and emotions. They live in pretty identical families, where they do the same things. Everyone has brown eyes in this community except for Jonas and the Newchild, who both have light eyes. This is symbolic for a couple of reasons. One reason is because it shows or hints to the fact that there are some differences in this community meaning that maybe there are some weak links. Another reason this is symbolic because it could be seen as a way of foreshadowing that Jonas and the Newchild are somehow different from everyone else.