Death, we fear, because it is unknown, but death also makes us think, Should we live a pios life? Should we be altruistic? We have been told all of our lives that we should, so some great plainof eterna happiness hits us, or we will wake up as another being. But, in my opinion, I say that due to no sensory input, and no brain to provide conciousness, ourselves as we know it, through our eyes, go into complete nothingness, with nothing to see, so there would be no colour, black is a colour, so you wouldn't see black either, you would see no colour. No sound, sso it wouldn't sound like an echoey cave, no smell, no perception, at all.
You wouldn't even know you were dead, your brain wouldn't function, you'd have no memory, no anything. The closest thing I have to compare is a dreamless sleep, that fits most of the criteria, and in the end, jhust sleeping without dreams forever isn't that bad, is it??
I too have been thinking of what it would be like to not exist. I've had my wisdom teeth removed recently and was put under so I could fall asleep to not feel the pain. When I fell asleep it seemed as if only a second passed while I saw black (there was no dream). When I woke up I found out later that I was asleep for about an hour. It got me to think about nothingness. Its really hard for me to think about since I am alive and cannot think into nothingness. Like you said there is no color (even white) or sound, or anything. I feel as if it would be horrible to sleep forever without dreams, it sounds downright scary. (Probably why they made religion) I think that everything that has a life and conscious goes somewhere when they die.