In example embodiments, an optical system includes a waveguide having a first surface and a second surface substantially opposite the first surface. A reflective diffractive in-coupler is provided in the waveguide between the first and second surfaces for coupling blue light. A first transmissive diffractive in-coupler is provided in the waveguide between the reflective diffractive in-coupler and the second surface for coupling red light. Some embodiments further include a second transmissive diffractive in-coupler on the first surface for coupling blue light at high incident angles. Green light may be coupled by one or more of the in-couplers. The waveguide may further be provided with corresponding diffractive out-couplers for use in a waveguide display system.