Rainbow can be used either as a standalone synth, or as a VST2.0 plugin (it has been tested with Cubase 3.7, Logic Audio Platinum 4.7, FruityLoops 3.0, and Orion 2.2). Standalone operation requires a soundcard with DirectSound drivers, and a midi controller.

Thanks to an original mixture of FM, AM, additive and substractive synthesis, Rainbow is able to produce a wide assortment of sounds, from analog emulations or synthesized drums to 80's electric pianos or synth basses.