When I changed the default theme I saw someone say I should name the classic theme "AMOLED". Apparently, the theme was so dark to a lot of people that it appeared black! I guess my designer's eye and working on photon for over a year made me not notice this.
The classic theme uses a very dark gray for the main background, and an even darker gray for the sides. There was never any black, except in very very early versions of Photon.
On some devices I could not tell.