Eva Murzyn asked people in their mid-fifties to rate both the amount of colour in their dreams, and how much black-and-white television they watched during their childhood. 25% of those who only say monochrome television when they were young dreamt in black and white, compared to just 7% of those who had access to colour television.
Erections happen during even the most mundane of dreams, and are not necessarily the sign of an erotic adventure.
David Foulkes From the University of Chicago, invited volunteers to his sleep laboratory, taped open their eyelids and asked them to fall asleep. When the volunteers started to dream, Foulkes would place various objects in front of their eyes. The volunteers were then woken up, asked to report their dream, and quizzed about what they thought had been showed to them. The volunteers saw nothing, and the objects didn’t crop up in their dreams, suggesting that you become blind when you dream.
Source: Night School by Richard Wiseman