In the DVD, her left eye (left from her perspective, not the viewer's) appears green....but you can't tell because they do such a great job of always putting her in dim lighting.
Hey Condrum, if you're writing a Serena story, it really doesn't matter what color each eye is. Remember it's Serena's eyes you're gonna be talking about, not Jane's.
And if YOU ARE writing a story, post it, because I would love to read it