Why are all ghosts white?

Some of the Phenomena we CALL "Ghosts" are also greenish or blueish in addition to being white.---All colors from the electrical spectrum---Most look white simply because the illumination is very weak.    The colors are likely a clue to their TRUE nature---being some kind of  atmospheric electrical phenomena that is not in our Science books yet.-------Observed for millennia, and traditionally attributed to "Spirits of the dead", by the surprised and superstitious observers.----------And said not to exist at all by irrational "Skeptic types" who say, since Ghosts do not exist, neither does any unknown natural phenomena, people take for Ghosts exist either.----Think about that for a while.   

Who tried to tell you there are no black ghosts, and why did you decide to believe them?

According to some of the ghost shows I have seen, there are some but it seems they aren't as eager to share their experiences.  

nobody can actually see ghosts that is why the human eye can not pick up what they really look like

They aren't.

 I've seen 4 black slaves locked in a warehouse in around 1780. They were the property of the shipping company and as such were locked in overnight. Unfortunately for them the ship they had just unloaded had a lot of deaths on board, and the bodies were wrapped up in sailcloth (looked like mummies - but still human shaped). - but as they had to be kept securely until they were claimed, they were stacked in the warehouse with the slaves.

 Not nice and as you would expect they were terrified about it. Hence the imprint.

You may think this is just my imagination, but I saw this in a concrete car park. I didn't know there was a brick warehouse on that spot when I saw what I did. What I saw a was a brick building with heavy sliding doors, but very narrow slit windows- with no glass. And a dirty brick floor. I found a very old photograph and a map of the docks which proves it exists.

I also didn't know they kept or used slaves but it was in their records, and I didn't know about the way they dealt with bodies until I researched it after the sighting. So all the evidence matches what I saw.

They only appear white just like clouds do....it's a light refraction of vapor.

Why are there no black ghosts?    Because there are no ghosts at all.

As ghosts are entirely fictional, they can be any colour you like. One thing to consider is that most people who claim to see ghosts do so when it is dark so they would only see white ghosts. Black ghosts would not show up well at night.

I think there were some special episodes of "Casper" with black ghosts.

Dude, watch "Ghost Adventures". They capture shadow people on film all the time. It's creepy as h*ll!

"My name is Zak Bagans..."