A tape cassette, comprising: a housing including a top wall (31 A) having a top surface, a bottom wall having a bottom surface, and a side wall (31 C), the top wall and the bottom wall having a rectangular shape whose longitudinal direction is a left-and-right direction of the housing, the top wall, the bottom wall, and the side wall defining a periphery of the housing; at least one tape (55, 57, 58, 59) mounted in a tape housing area (33A and 33B) defined within the periphery; and a color indicator portion disposed between the tape housing area and the periphery, and in a specified area adjacent to the tape housing area on a rear edge side of the bottom wall, the color indicator portion indicating color information relating to the at least one tape, characterised in that the color indicator portion includes a plurality of lateral information sections (Y1 and Y2), the plurality of lateral information sections being a plurality of strip-shaped sections extending along the left-and-right direction of the housing and aligned in a front-rear direction of the housing, wherein: a presence or an absence of a first protrusion that protrudes downward from the bottom surface and is formed in a first lateral information section indicates, as the color information, a base material color of the at least one tape, the first lateral information section being one of the plurality of lateral information sections and extending along the left-and-right direction adjacent to the rear edge of the bottom wall, and a presence or an absence of a second protrusion that protrudes downward from the bottom surface and is formed in a second lateral information section indicates, as the color information, a print color of the at least one tape, the second lateral information section being another of the plurality of lateral information sections and extending along the left-and-right direction in front of the first lateral information section. a housing including a top wall (31 A) having a top surface, a bottom wall having a bottom surface, and a side wall (31 C), the top wall and the bottom wall having a rectangular shape whose longitudinal direction is a left-and-right direction of the housing, the top wall, the bottom wall, and the side wall defining a periphery of the housing; at least one tape (55, 57, 58, 59) mounted in a tape housing area (33A and 33B) defined within the periphery; and a color indicator portion disposed between the tape housing area and the periphery, and in a specified area adjacent to the tape housing area on a rear edge side of the bottom wall, the color indicator portion indicating color information relating to the at least one tape, characterised in that the color indicator portion includes a plurality of lateral information sections (Y1 and Y2), the plurality of lateral information sections being a plurality of strip-shaped sections extending along the left-and-right direction of the housing and aligned in a front-rear direction of the housing, a presence or an absence of a first protrusion that protrudes downward from the bottom surface and is formed in a first lateral information section indicates, as the color information, a base material color of the at least one tape, the first lateral information section being one of the plurality of lateral information sections and extending along the left-and-right direction adjacent to the rear edge of the bottom wall, and a presence or an absence of a second protrusion that protrudes downward from the bottom surface and is formed in a second lateral information section indicates, as the color information, a print color of the at least one tape, the second lateral information section being another of the plurality of lateral information sections and extending along the left-and-right direction in front of the first lateral information section.