Why does Edwards eyes turn red in new moon?

If you've read the books, they say in the beginning of the series that vampires that havn't eaten (or had blood) lately, their eyes turn crimson. All newborn vampires start out like this. Before Bella opens her eyes, the story implies Bella has died. But at the last second, she opens them and they're red. This shows she has been turned into a vampire which opens up for Breaking Dawn Part 2.