An object of the present invention is to provide a processed flour food which is excellent in safety and cost respects and which contains added bilberries capable of stably coloring the processed flour food bluish purple, and a method of coloring the food. The present invention is directed to a processed flour food containing added bilberries, to which bilberries are added in an amount of 5% to 30% with respect to a weight of all materials to color the processed flour food bluish purple, and as a method of coloring a processed flour food containing added bilberries, the method being characterized by comprising: a harvesting step of freezing picked bilberries and then removing foreign matters therefrom; a processing step of crushing the frozen bilberries after the harvesting step and adding an aroma and sugar to the bilberries to mix them; a storing step of sterilizing each constant amount of the packed bilberries after the processing step and passing the bilberries through a metal detector to store the frozen bilberries; and a using step of thawing the bilberries after the storing step to blend the bilberries with the processed flour food.