Sterilize six 8-ounce canning jars and lids according to the manufacturer's instructions. Heat water in a hot water canner.

Place bell peppers and jalapeño peppers in a large saucepan over high heat; stir in vinegar and fruit pectin. Bring to a rolling boil, stirring constantly. Stir in sugar; bring back to a rolling boil, stirring constantly. Allow to boil for 1 minute, then remove from the heat and skim any foam off the top.

Quickly ladle jelly into sterile jars, filling to within 1/4-inch of the tops. Cover with flat lids and screw on rings tightly.

Place jars in the rack and slowly lower jars into the canner. The water should cover the jars completely and should be hot but not boiling. Bring water to a boil; cover the canner and process for 5 minutes.