A light fixture, preferably for stage, is provided with a source assembly configured to generate a light beam mainly along an emission direction; and with at least a first optical assembly arranged downstream of the source assembly along the emission direction; the first optical assembly comprising at least one mixing device configured to mix the light beam passing through it; the mixing device comprising an optical mixing element and a moving device configured to move the optical mixing element between a position of non-interference with the light beam emitted by the source assembly and at least one position of interference with the light beam emitted by the source assembly.