How to get a black tail to go white!

We have an Appaloosa with lots of black in his tail. He is a part of a four up of whites and needs to have a white tail. Any ideas on how to get his tail white for this show? Also, does anyone know of good mane and tail extensions since two of the whites have long manes and the other two have short thin ones?
Thank you for any and all help.

I fail to see why his tail needs to be white. Please explain.

Re-read your psot, and im still not understanding some things. You have 4 appaloosas and one of them has black in his tail? If so, why is this a problem? And you are looking for extensions for... 2 of the 4 horses sicne their manes are different? Just clarifying for the next person.

I read the OP's post to mean that the four horses work as a team (not familiar with the term "four up," so I'm not sure if we're talking about a 4-horse hitch or some kind of drill team) and that the OP wants them to all have uniform looking manes and tails.

IMO, you are never going to make a black tail look naturally, acceptably white, so I would focus more on making tail lengths uniform and not worry about color. Ditto that with mane thickness.

I agree.

Them moving with a similar stride and such with well fitted matching tack is far more important than a few tail hairs.

If you are buying extensions for a couple of them why not buy extensions with some black in them? Then all the tails will match.

The horses are being used in a movie. A four up consists of 2 horses in front, the leaders, and two in back, the wheelers. Three of the horses have white tails and the fourth has a lot of black in his. We are just trying to find a temporary way of coloring the black in his tail to match the others.

Can you simply braid away his black hairs and add a white extension to make for it.

I can not think of a way to bleach tail hair.

Can't you get a spray paint for hair? I would do some research for that on line

Really?

Maybe This?