and what? Shades of gray) Grayscale lines) If desired, you can distinguish ;) I remember for some time in one game on the video console sounded like bullying "red gates mean this, yellow - then, blue - the third", because the TV was staareenky and its standard did not allow to extract a color image from the new console X)

Oh, I remembered how I was playing on the monitor :) There was one toy, I don't remember the name, where in the course of the matter it was necessary to enter a burning dark room and insert some detail there somewhere so that everything didn't explode. But the trick was that there was a red light on a black background in that room. Thus e. on the monitor - black on black. You enter the room and everything, a black screen. and Ura.
It was done exclusively by remembering - to take three steps, to jump up, to stretch, to take two steps, to bend, etc. And the time is limited, in a few minutes everything explodes if you don't have time to insert a detail. And it has passed! Indeed, childhood is the happiest time.