"How do I use it?"
The dye is very easy to use. All you have to do is spray it on, rinse out the excess, and you're done. Also, you can create special effects like streaking, fades, and layered colors. (Instructions for these techniques will be included with the dye.) Additionally, the colors can be combined and overlapped without dissolving the previous layer; a major drawback of the old "rubbing alcohol" method.
"How long does the color last?"
Just like the marker method, the color is permanent. The only way to remove the color is with rubbing alcohol, or cleaners which contain a large amount of alcohol or ammonia. (Some styling products which contain a lot of alcohol, like hairspray, may partially dissolve the color, but you can either rinse out or wipe off the excess.) The color will not rinse out in cold water, so it is safe to wash your wig.
"How many colors are there?"
Right now there are 16 colors (six of them shown to the right...), based on the ones I've found are most commonly needed. More colors will be formulated as the need arises, but with just these few colors, you can create many custom combinations based on the starting fiber color.
"How do I know what color of wig to start with to make the color I want?"
If you'd like to see how the color will look on your wig without buying an entire bottle, I'd suggest getting a "sample sized" vial from the wig supply store to try it out. There is also a testing chart at the bottom of this page, so you can get an idea for what a particular combination might look like.^_^
"Do I have to start with a white wig?"
Of course not. The dye will work on any color of synthetic fiber, but the darker the starting shade, the less change you will see. (The dye can not lighten the starting color, it can only tint it.) There is no visible difference when the dye is used on black fiber.
"How much dye does it take to color a wig?"
In my experience, one 4oz (118mL) bottle is enough to dye one entire shoulder length wig. (Like the Femme Fatale style at Amphigory.) But some folks reccomend two bottles for that length. Longer wigs will require more dye. Also, the color is translucent, so if you are going for a very dark tone, you may need to do more than one application.