I have a Bestop hard top, white in color, on a '95 Suzuki Sidekick.  Would like to trade for a black one.  Or, does anybody know how to "color" one....they won't hold paint.   I live in Kentucky.

Just Paint it!

I've painted a couple of them.

One from White/Gray to Black and one from faded Black to Black.

Both turned out great!

I think I used Krylon Bumper/Plastic paint? I can't remember. Just wash and degrease everything good first.

I think it took about 3 cans. Get an extra just in case.

Thanks about the paint advise.   It's just that everybody said the plastic won't hold paint!  But, I'll try most anything a couple of times!  What's the longevity on your paint job(s)?

The paint job is only as good as the prep job, like he said take your time and wash it, degrease it, let it dry before painting it.

Krylon Fusion is designed for plastic.  I know lots of folks have used it on ATV plastic.
http://www.krylon.com/products/fusion_for_plastic/

Most bumper skins are plastic and they hold paint forever.

There can be issues with painting old fiberglass. The resin used simply breaks down and has contaminated the present paint with outgassing. This can be rectified with sanding the old paint off and applying some new resin and sanding that down, priming and then applying new paint. Old Corvettes are notorious for this!