The present invention is directed to an illumination device (24) for a vehicle (46), comprising a light generating unit (12), comprising at least a first light source (141) providing light of a first color, and a second light source (142) providing light of a second color, and a mixing unit (16) having a first end (18) and a second end (20), wherein the light provided by the first light source (141) and the second light source (142) is coupled into the mixing unit (16) at the first end (18), the mixed light is leaving the mixing unit (16) at the second end (20), and a reflection surface (22) extending between the first end (18) and the second end (20) on which the light coupled into the mixing unit (16) is reflected, wherein the reflection surface (22) has diffusive properties (D) such that the light coupled into the mixing unit (16) is diffusively reflected. Moreover, the present invention relates to a vehicle (46) comprising such an illumination device (24).