It's usually around a week or less from blueing over to actual shed. First the snake will go blue, then turn more or less to normal color, then a day or two after it will shed.

65% is good, maybe a little higher even. I've heard of people putting it to 70%. If he doesn't shed easily, you can soak him in lukewarm water for an hour or so, just make sure it's not deep enough where he has to swim.