The invention provides a lighting unit comprising a source of blue light, a source of green light, a first source of red light comprising a first red luminescent material, configured to provide red light with a broad band spectral light distribution, and a second source of red light comprising a second red luminescent material, configured to provide red light with a spectral light distribution comprising one or more red emission lines. Especially, the first red luminescent material comprises (Mg,Ca,Sr)AlSiN3:Eu and/or (Ba,Sr,Ca)2Si5-xAlxOxN8-x:Eu, and the second red luminescent material comprises K2SiF6:Mn.