The invention discloses a high efficiency incandescent and Compact Fluorescent (CFL) bulb replacement LED lamp having a good color reproduction. The LED light bulb includes two groups of semiconductor light emitters and a luminescent material to emit four different spectrums of light. The two groups of semiconductor light emitters are enclosed around an interior wall of the light bulb housing, which has a plurality of fins at an exterior surface for effective heat dissipation. A high reflective member having a dome shape in the center is disposed under the two groups of semiconductor light emitters to redirect the emission and excitation lights from the two groups of semiconductor light emitters and recycle the backscattered light for multi-spectrum light mixing. The LED-light bulb further includes a single power line connecting to the two groups of semiconductor light emitters and a high efficiency electrical AC/DC conversion and control device. The light bulb has a diffuser dome for an output window and a conventional Edison-mount screw-type light bulb socket, a conventional fluorescent tube coupler arrangement or a conventional halogen MR-16 socket arrangement connecting to an AC power base. If a voltage is supplied to the AC/DC conversion and control device, a mixture light from the diffuser dome produces a warm white light with a color rendering index of at least 85 and a luminous efficacy of at least 80 lumens per watt.