I hereby predict "LED-paint". It is a mixture of luminescent particles, semi-conducting liquid and maybe some measure of resonating metal particles. You paint t

I hereby predict "LED-paint". It is a mixture of luminescent particles, semi-conducting liquid and maybe some measure of resonating metal particles. You paint the wall with this paint and then let a computer and a camera learn how to make lights blink by generating suitable wave patterns and frequencies. There after you can show whatever you want on the wall.