Maybe the critical question is: If no light at all comes from the object, is that the same as it being dark, or is it a complete lack of stimulus?

If the brain receives noise, it fills in the blanks (http://www.sciencedaily.com/releases/2000/06/000601164617.ht...). In sensory deprivation, the brain also fills in the blanks (would cite but ended up finding a ton of supporting material in a web search, including an interesting study about the effects of anxiety on amount of hallucinations).