The invention relates to a top-emissive organic light-emitting diode (OLED) (10) arranged to emit light having different emission colours, comprising a multi-layered structure provided with a first electrode, a second electrode and a functional layer enabling light emission disposed between the first electrode and the second electrode, wherein thickness (H1, H2) of the functional layer is modulated by allowing at least a portion of the functional layer to interact with a thickness modulator (5a, 5b, 5c), wherein the functional layer comprises a hole injection layer or the electron injection layer.