You can measure heat, you can't measure cold, because it is the absence of heat...you just measure LESS heat. Heat is a measure of energy...cold is a way of characterizing less heat, but is not a thing. You cannot stop heat from moving, it always goes to where there is less heat. IOW, the cold doesn't come in, the heat goes out. As to black, it depends on whether you're talking additive or subtractive - in a pigment, black is the absorption of all colors, in light, it is the absence of all light frequencies. Vacuum is a measure of matter...the less matter, in a given volume, the more vacuum. WHen you remove the matter in a vessel, you are creating a vacuum, but it's a lack of matter we call a vacuum for simplicity's sake.
WHen trying to protect a water line, you need a way to trap heat. INsulation can slow the diffusion of heat, but it won't do that forever...things try to balance out - the heat diffuses, making everything closer to the same temperature. It helps to think that way when trying to keep your heat where you want it...the water in the pipe only has a limited amount of heat in it. Unless you can preserve it all or slow it dissipating, it can freeze. That's one reason why opening a faucet and letting it drip a bit might prevent it from freezing...the water being drawn from below the frost line (hopefully) has enough heat in it to overcome that lost so it doesn't freeze once above ground. WHen conditioning your house, in the summer, you remove heat from the inside but really aren't creating cold. In the winter, you're adding heat to the inside (either by concentrating it with a heat pump from outside or creating more heat with either combustion or electrical resistance). How much you need depends on the delta between the inside and outside, but all you're doing is moving heat.
It's a matter of perspective...looking at it like a scientist or a layman. Sometimes, you need a bit of both.
