Firstly, there is no Heaven or Hell, they are metaphors for states of being. Enlightened means you are moving to a personal condition called Heaven, ignorant and self-centred, you are moving to a state of being called Hell. Jesus also referred to it as being dead, "let the dead bury the dead. . . ."
The 144,000 is a symbolic number to indicate that the new returned Jesus with a new name and a new religion will attract a great mass of followers, disciples, etc. Jesus had 12 disciples, but when a figure like Jesus returns, so profound will be the potency of His word that it will have disciples of the order of 12 x 12 x 1000. This is not literal, rather it speaks to the potency of this new religion under a new Jesus.
The numerical value of 144,000 is 9 and 9 is the number of perfection and unity and the so called Second coming of a new Jesus like figure is said to usher in a universal religion of perfection and unity.
The colour of humans is of no significance, black, white or brindle, male and female, all one. As for 144,000 JWs going to heaven, there is no limits to the imagination that some religions have. I might add that a great many more than 144,000 JWs have put their hands up and claimed to have a ticket to heaven than there are places for them. Seeing as this is all just flights of fancy what real harm can it do?
