I was wondering if the mind can produce images or colors that the eyes cannot see. I have recently started practicing advanced vision control (AVC), which is when you manipulate your environment so much that you actually start seeing other things. AVC can be mastered over a period of time so that people can eventually manipulate the other senses and sort of create a lucid dream while awake. While practicing with my eyes closed in a dark room, I have noticed that I am seeing bizzare colors, mainly purplish/blue ones that seem to glow very brightly. They are so hard to describe because I have never seen colors quite like them. So are these colors impossible to actually see, or are they just exaggerations of colors I've seen in real life? If anyone is an expert on advanced vision control, any input would be greatly appreciated.