While you can google different recipes, I use the following:
2 cups white sugar
1/4 cup water
1/2 cup lemon juice

Boil the mixture in a saucepan for about 15-20 minutes, or until it looks amber-colored. Don't be afraid to take it off too early. You can always re-heat it in the microwave if it's too thin. Pour a thin layer of the mixture into a shallow bowl to cool off. Wait until it's almost room temperature, just slightly warm to the touch.

Pick up a small amount and roll it around like a ball between your fingers. It should be slightly sticky but still roll up easily, if it just sticks to your fingers or oozes off, it's too soft. If it's too soft, put it in the microwave for about 30 seconds, let it cool, and test it again, but don't put the sugar in the microwave for more than 30-45 seconds, or it might burn and be ruined.

Squish the ball down onto the area you want to wax and (this is the important part) smooth it out OPPOSITE the direction of hair growth!! Apply slight pressure and keep smoothing the same direction 2-3 times. Did it hurt a little? Then you probably did it right.

With your other hand, pull the skin taut. Grab the edge of the squished ball, and pull it in the direction of hair growth. It might take you one or two pulls to get the sugar off, but if it just stretches apart and doesn't take any hair off your sugar is too soft and needs to be cooked more.

Roll the sugar you just used back into a ball and do the same thing in a different area. If the sugar ball starts getting too soft or sticky from the warmth of your hands, just toss it aside and make a new ball. You can go back to the old one once it hardens if you want.

Be sure to shower before you wax to ensure that the wax sticks as well as possible. Though it varies from person to person, results typically last about 4-6 weeks for me.

Color Fix by Jheri Redding is designed to remove unwanted permant hair color, and controlled usage allows color correction to specific areas, either full or slight color corrections.

Loreal Color Zap gently washes away all permanent haircolor. Ideal for color correction, removal of dark shades, muddy, uneven results or color build up. Leaves hair ready for immediate re-coloring. Loreal Effasol Color Remover washes away permanent haircolor, leaving hair ready for recoloring. Can be used with water or developer.

Jerome Rusell's Punky Color Punk Off is an easy to use gel that will cleanse your skin from hair dye stains.

Roux Clean Touch is a gentle formula that removes haircolor from skin and scalp. Removes excess color from hair ends and assists in removing stains from clothing.

Home remedies include this one:

Hot Oil treatments, hairspray, shampooing and exposure to water will gradually fade hair dye.

To remove the last bit of residue or stain on the hair (or to get color out immediately) make up a small batch of bleach mixture and add it to 2 tablespoons or so of shampoo in a cup. Stir it up.

Shampoo your hair with this mixture, "kneading" the hair. Start at the roots and work your way down to the end, and then back up.

You should see the color disappear right before your eyes.