The present invention relates to an illumination device comprising a number of light sources generating light and a number of light collecting means adapted to collect the generated light and to convert the collected light into a number of light beams that propagate along an optical axis. The light sources are arranged in a first group and a second group of light sources and the first and second group of light sources emits light having different spectral distribution. The light sources and the light collecting means are movable in relation to each other and can be positioned in a number of mixing positions, where in the number of mixing positions the light collecting means are adapted to collect at least a part of the light emitted by the first group of light sources and at least a part of the light emitted by said second group of light sources and to convert the collected light into number of mixed light beams.