The Eyes Have It
An original editorial by Rye
Now we obviously know that Harry and Lily both have green eyes, and that Voldemort has red eyes. Avada Kedavra's light is green, as well as the Dark Mark. Is there a connection? There might be some significance to Harry and Lily being attacked by Avada Kedavra and having green eyes.
The resurrected Voldemort has red eyes. We don't know what Tom Riddle's eyes look like. JKR has talked about his eyes, but does not say what color. JKR usually makes a point of saying someone's eye color, so this could very well be important information. The only thing JKR says about Tom's eye color is that "there was an odd red gleam in his hungry eyes" (CoS, American version). So this may imply that Tom's eyes weren't red at the time, which would have been somewhat creepy. But they got red during the rebirth process in Goblet of Fire. Why would they do that?
Superstition says "red and green must never be seen." Green is unlucky
(look what Harry's been through!), and putting it with red is a stronger curse. Which could mean very bad luck and bad things to come? And things that have passed already in previous books may be part of the red-green idea.
Red is evil-(Voldemort)
Green is unlucky-(Harry)
Red and green are very unlucky-(Battles with Voldy always leave Harry hurt)
Things look pretty grim don't they? That is saying that Harry might die because of green and red. It's also saying that for Voldemort too. He's suffered a lot of defeats also: when he gave Harry the scar, the destruction of the Sorcerer's Stone, his Death Eaters in jail, etc. So there is an equal chance for both to be killed.
BUT... Gryffindor's colors include red, while Slytherin's colors include green. Is this just coincedence? Does it mean unity or division later on? Does the red-evil, green-unlucky comparison still apply?
What I have conjectured is that Harry and Voldemort both have an equal chance of dying in battle. All through their eye colors! I hope this little article made some things clearer, as it did for me learning about it.
Other eye colors don't especially seem to matter. I mean like blue eyes or brown eyes. I think the only emphasis is red and green eyes, which is pretty obvious from the books. But don't stop looking at eye colors, as JKR could still surprise us.
Thanks to: Shadowlight and Laurelin for information