A palimpsest comes from the ancient Greek palimpsesetos, literally meaning “scraped clean and used again.” Archeologist Paul Basu used the notion to express how the constructed past is a projection of our present mindset: “practical and discursive memories from different periods become intermeshed such that one period is remembered through the lens of another.”
The History Channel's latest ads dabble in similar ideas: different times in same spaces are superposed suggesting we forget but need to remember, as well as marking how the black and white past is a creation of the colourful present.