A low-beam-color-temperature-variable headlight unit comprising: a case; a condenser lens including a low-beam output surface configured to output a low beam and a light receiving surface located behind the low-beam output surface with respect to a front-back direction of the case; a high-color-temperature light emitting diode located inside the case, at a position nearer to a center line of the light receiving surface than to a right end and a left end of the light receiving surface with respect to a right-left direction of the case, the high-color-temperature light emitting diode being configured to illuminate a first illuminated area with light passing through the light receiving surface and output from the low-beam output surface, and the high-color-temperature light emitting diode including a high-color-temperature light emitting surface from which high-color-temperature light is emitted; a low-color-temperature light emitting diode located inside the case, side by side with the high-color-temperature light emitting diode in the right-left direction of the case, at a position nearer to the center line of the light receiving surface than to the right end and the left end of the light receiving surface with respect to the right-left direction of the case, the low-color-temperature light emitting diode being configured to illuminate a second illuminated area, which overlaps the first illuminated area at least partly, with light passing through the light receiving surface and output from the low-beam output surface, and the low-color-temperature light emitting diode including a low-color-temperature light emitting surface from which low-color-temperature light is emitted; and a low-beam-color-temperature control unit capable of adjusting the color temperature of the low beam by adjusting the quantity of light emitted from the high-color-temperature light emitting diode and the quantity of light emitted from the low-color-temperature light emitting diode. a case; a condenser lens including a low-beam output surface configured to output a low beam and a light receiving surface located behind the low-beam output surface with respect to a front-back direction of the case; a high-color-temperature light emitting diode located inside the case, at a position nearer to a center line of the light receiving surface than to a right end and a left end of the light receiving surface with respect to a right-left direction of the case, the high-color-temperature light emitting diode being configured to illuminate a first illuminated area with light passing through the light receiving surface and output from the low-beam output surface, and the high-color-temperature light emitting diode including a high-color-temperature light emitting surface from which high-color-temperature light is emitted; a low-color-temperature light emitting diode located inside the case, side by side with the high-color-temperature light emitting diode in the right-left direction of the case, at a position nearer to the center line of the light receiving surface than to the right end and the left end of the light receiving surface with respect to the right-left direction of the case, the low-color-temperature light emitting diode being configured to illuminate a second illuminated area, which overlaps the first illuminated area at least partly, with light passing through the light receiving surface and output from the low-beam output surface, and the low-color-temperature light emitting diode including a low-color-temperature light emitting surface from which low-color-temperature light is emitted; and a low-beam-color-temperature control unit capable of adjusting the color temperature of the low beam by adjusting the quantity of light emitted from the high-color-temperature light emitting diode and the quantity of light emitted from the low-color-temperature light emitting diode.