The invention relates to a lighting arrangement (1) for illuminating an area under mesopic conditions. The lighting arrangement has one or more LEDs (6) emitting substantially monochromatic light in a first wavelength region. The lighting arrangement further has one or more LEDs emitting (8) substantially-monochromatic light in a second wavelength region. Aforementioned combination of LEDs is such that, in use, the light provided by the lighting arrangement has an S/P-ratio greater than 2.