<p>A light source combines colored light from different LED sources to provide white light output. Multiple LEDs emitting light at different peak wavelengths may be disposed on a flexible substrate, the LEDs being close to an aperture formed in the substrate. Multiple mirrors, including at least one dichroic mirror, are oriented to reflect light from the multiple LEDs into the aperture. The flexible substrate includes a dielectric layer having a cavity region and an adjacent neighboring region that is thicker than the cavity region. The aperture and the multiple LEDs are all disposed in the cavity region of the dielectric layer. An integrating rod may be coupled to the aperture to receive the reflected light from the multiple LEDs.</p>