Speaking of the yellow banana, people do a lot of filling in with color.

One of Dennett's points is the misleading notion that our mind "fills in". In the case of vision, our brain doesn't "paint in" missing visual data, such as the area in our field of vision not captured by our fovea. Our brains simply lack epistemic hunger for such information in order to perform the tasks that they need to.

I've noticed that this account potentially explains how color works in my dreams. My dreams aren't even black and white - the visual aspects are mostly just forms. However, if the color has meaning or emotion, it's there. I recently had a dream where I looked up at the sky, and the moon was huge and black, moving in a rapid arc across the sky then suddenly diving into the Earth causing an apocalyptic wave of dirt to head towards me. The vivid blackness was present, because it meant something to me emotionally. The houses, in comparison, merely had form, but no color. In any case, it seems that the question "Do we dream in color?" can't be answered adequately if using a "filling in" model of the mind.