Food color, green; optional Place jalapeno peppers, green peppers, and vinegar in bowl of food processor. Using metal blade and quick on and off turns, finely grind peppers. Scrape pepper mixture into heavy saucepan. Stir in sugar. Cook over high heat, stirring constantly, until liquid comes to a full, rolling boil. Boil for 10 minutes. Remove from heat. Stir in liquid pectin, red pepper flakes, and 2 to 3 drops food coloring, if desired. Immediately pour into hot sterilized jars and vacuum seal. (Hot water bath method, or may be refrigerated up to 6 weeks).