I just watched this video that explains how to do it. : http://youtu.be/wG_9slqCO7M
I will also try peroxide sprayed and then clean with a white rag with water. Peroxide will take the color away so you need to be very careful and try it first.If the carpet is made out of wool or silk, use professional help as water and different products might damage them.
@Sherrie This is right up your alley
I went to the Carpet institution of America. You do this in steps to find the right solution.
This is the first step, try this before going to the other steps. Be sure to use a white cloth, or paper towel (paper towel can not have ink on it because it will transfer to your carpet). Remember to dab. Don't rub the stain. And blot. Don't use more soap than it calls for because its harder to get the soap out later.
If it has chocolate you can use a dry cleaning solution. Since I am thinking this needs to be done in several steps
Step 1. Try this first.
Detergent Solution – Mix 1⁄4 teaspoon liquid, non-lanolin, hand dishwashing detergentwith one cup warm water. Mix professionally formulated detergent solutions accordingto the manufacturer's recommendations. NEVER USE A STRONGERCONCENTRATION, (increasing the amount of detergent beyond the recommended leveldoes not increase cleaning performance but makes the complete removal of detergentmore difficult), always use a detergent with a pH of less than 10. Thorough rinsing isnecessary to remove detergent residues that may cause rapid soiling. You may need torinse with warm water several times to completely remove residues. (See residueprecautions.) Care should be used in selecting a detergent. Never use a laundrydetergent of any type because laundry detergents may contain optical brighteners(fluorescent dyes) that dye the fiber. Do not select an automatic dishwashing detergent.
If this didn't work do step 22.Vinegar Solution – Mix one cup of white vinegar (a 5% acetic acid solution) and onecup of water. This is used most often to lower the alkalinity caused by detergentsolutions or alkaline spills removing residue. A professional solution may also be used(available from sanitation suppliers).
Then do this.
3. Rinse with warm water. Keep rinsing and blotting.
If it still isn't working this removes chocolate
Volatile Solvent (A fast evaporating dry cleaning fluid) – Exercise caution when using asolvent. A non flammable spot removal solution is preferred. Never pour a volatilecleaning solvent directly onto the carpet. Volatile cleaning solvents will destroy the latexthat holds the carpet components together. Non-volatile Solvents – (Referred to as paint, oil and grease removers.) This type ofcleaning solvent evaporates slower for more effective cleaning. Non-volatile solventscan leave residues that may cause rapid soiling. When using a non-volatile remover,always rinse the area thoroughly with a volatile solvent. Many nail polish removerscontain a non-volatile solvent and can be an effective cleaning solution. Nail polishremovers containing amyl or ethyl acetate also contain alcohol to assist in rinsingresidues. See residue precautions.
But if its is even worse I would call a rug cleaning company. They have even gotten fingernail polish out of my rugs.
Here is the link for anyone else it is a professional link my first response is to call your rug manufactory to find cleaning solutions.