I love talking about dreams. And better yet, my favorite part of your post is at the end, you're right, there is so much we cannot see in a variety of ways, we can only see a limited range of color, light, and other things. There are other dimensions.
On a generic level, dreams are our brain sorting short-term memory into long-term memory. However, I wonder if people can also interact with other humans or other things through deep-sleep REM dreaming. I wonder if things can be transmitted to us via us.
Well, I suppose that goes along the lines of Jung's theories about dreams; that the messages in our dreams are often about our subconscious trying to "send a message" to our conscious awareness.