Multilevel modulations are becoming attractive, not only for metro-core optical communications, but also for the access sector. Designing cost-effective, easy-to-integrate multilevel modulators is mandatory to support high-bandwidth access interconnections, which may also require colorless operation. In this work, we propose a novel colorless multilevel transmitter architecture, based on reflective semiconductor optical amplifiers (RSOAs) which meets the above criteria. In our architecture, Fig. 1(a), the in-phase (I) and quadrature (Q) components of the optical QAM signal are obtained by direct modulation of two RSOAs, using the currents II and Iq. The RSOAs are coupled together and fed by the same seed source so that a π/4-phase shift in the in-phase path allows the output field to comprise two quadrature components.