[en] Practical applicability of dosimetric color films available as Nitto Radocolor in commerce have been examined. The characteristics for dosimetry were studied using gamma-rays from Co-60 sources. The films can be stored without any deterioration unless they are exposed directly to sunlight or ultraviolet light. The dosage is easily estimated by comparing the irradiation-changed color of the film with a given standardized color chart. The dosage can be determined within an accuracy of 40% by the use of the printed color chart (Color Standard) supplied Nitto Co. and within an accuracy of 20% by the use of a color chart with color films which has been prepared by the present study. (auth.)