Why is it that some people only dream in black and white and sometimes red? Does it have anything to do with the light spectrum?
Hi freemind, er…don’t I know you? 
Interesting question. I’ve heard of people dreaming in B&W, but never red!
Does this happen to you often? I’ve never had anything but a full color dream in my life.
I know a lady that dreamed one time of a green sky and yellow clouds. The best we could figure is that somehow her mind had imposed a set of yellow sunglasses on her.
Black and white could be a reaction to watching old movies. Red, perhaps remembering a time when you were younger and looked at the world through red celophane?
No, not me. I have full color (sometimes strange colored) dreams. And about the red. Im not saying that they dream in all red but the few people that ive talked to that dream in black and white sometimes also see red. And its not like they try to or anything. They just have black and white dreams all the time.
I think it was O’nus (back at DV) who talked about the significance of color. From what I gather, people remember colors only when it’s truly significant (even if they don’t know why). I rarely remember specific colors in my dreams, but I know that I dream in color. It’s possible that people dream in black and white because that has some specific significance to their particular dream(s).
I can recall particular dreams where there was a general color “overlay” to the whole scene, often red or brown for some reason. Other than that…
Red is from the back of your eyelids.