# What Color Are Black Holes Really? (Yes, a serious question)

So I got into a mini-debate in science class today because I proposed that black holes aren't really black, they only look black because light can't reflect off them. But if you were to take the material that makes up that black hole and decrease it's density so that gravity isn't so strong that light can't reflect, then what color will this new object be? Think of it like this: if you put a red apple in a room that is completely pitch black, the apple will appear black but it's actually red (we just can't observe this because there's no light).

• If you decreased the gravity to the point light can reflect, it would cease to be a black hole – Jim Mar 1 at 14:30

• At some point during their life they will heat up enough to become visible, though. If we believe xaonon.dyndns.org/hawking, then a 5800K black hole has a radius of $3.141749\times 10^{-8}m$ (i.e. the size of a small virus), a mass of $2.115868\times 10^{19} kg$ (the mass of a large mountain and a luminosity of $7.959627\times 10^{-7} W$ (barely enough to be visible with the naked eye from a few meters, I think). One couldn't get close enough to see it with bare eyes, though, the gravity would be a killer at that distance. I might be wrong about that bit. – CuriousOne Apr 2 '16 at 2:56