I always took the line as Like a Ferris Wheel, (she was) full of blue green eyes. Like to me the lyric is remembering a specific ferris wheel lit up in the night sky with blue and green lights, it's such a vivid image that I swear I've seen it myself before. And he's likening her eyes to the same color and feeling he gets when he recollects that ferris wheel. At least, that's how I've always interpreted that, so it never really felt off in any way to me.