Howdy Oreo, I could not see for certain (the image and/or my eyes are too blurry), but it appears that it could be a little light bleaching. How close were they to the lights prior to being chopped?
I almost forgot, when I have had nanners, they have always turned dark, like the other buds, after harvest, but the 'sugar' leaves get bleached very easily, and stay that way after harvest.