In this "physical" reality generally people except color as an inherent thing that exists outside of oneself. Well when you think about it you realize that what we see is just a representation of reality percieved inside our brain by the visual cortex. Our eyes can recognize different wave lengths of light, but its our brain that creates colors and assigns them to the different wave lengths to create a coherent picture, and that is no objective process. The same goes for all types of stimuli, everything is experienced subjectively, its just a matter of how your consciousness processes stimuli and organizes it. Higher dimensions are just more complex ways of representing the same reality, just the next coherent picture.