A system comprising a recording medium and a playback device, the playback device comprising a configuration based on a data structure recorded in the recording medium, wherein the recording medium is reproduced by the playback device, the system comprising: a readout unit that reads out a main video stream where a main video has been encoded, and a sub-video stream where a sub-video, that is to be superimposed on the main video and displayed, has been encoded, are recorded in the recording medium, wherein the main video stream includes a first main video stream of a first luminance dynamic range (SDR) and a second main video stream of a second luminance dynamic range (HDR); and a playback unit that plays the main video stream and the sub-video stream that have been read out, wherein the sub-video stream includes bitmap data indicating a design of the sub-video and palette data specifying a display color of the design, the system characterized in that the palette data includes first palette data for the first luminance dynamic range used in case that the first main video stream is to be played, and second palette data for the second luminance dynamic range used in case that the second main video stream is to be played, wherein the second luminance dynamic range is broader than the first luminance dynamic range, wherein the bitmap data includes first bitmap data for the first luminance dynamic range, and second bitmap data for the second luminance dynamic range, and wherein the sub-video stream includes a plurality of sets, each set including a first sub-video stream including the first palette data and the first bitmap data, and a second sub-video stream including the second palette data and the second bitmap data. a readout unit that reads out a main video stream where a main video has been encoded, and a sub-video stream where a sub-video, that is to be superimposed on the main video and displayed, has been encoded, are recorded in the recording medium, wherein the main video stream includes a first main video stream of a first luminance dynamic range (SDR) and a second main video stream of a second luminance dynamic range (HDR); and a playback unit that plays the main video stream and the sub-video stream that have been read out, wherein the sub-video stream includes bitmap data indicating a design of the sub-video and palette data specifying a display color of the design, the system characterized in that the palette data includes first palette data for the first luminance dynamic range used in case that the first main video stream is to be played, and second palette data for the second luminance dynamic range used in case that the second main video stream is to be played, wherein the second luminance dynamic range is broader than the first luminance dynamic range, wherein the bitmap data includes first bitmap data for the first luminance dynamic range, and second bitmap data for the second luminance dynamic range, and wherein the sub-video stream includes a plurality of sets, each set including a first sub-video stream including the first palette data and the first bitmap data, and a second sub-video stream including the second palette data and the second bitmap data. <EOS>