An optical lens and method for designing the lens are disclosed. The lens includes a first surface and a second surface. Light emitted from multiple light emitting elements enters the lens through a central section of the first surface. The light can be reflected from a reflective central section of the second surface and/or undergo total internal reflection at an outer ring section of the second surface one or more times before exiting the lens through the outer ring section of the second surface. Upon exiting the lens, the light beam has a predetermined divergence angle and has a fairly uniform color in the far field even if the multiple light emitting elements have different peak wavelengths.
