LED lighting unit

A method of manufacturing an LED lighting unit, which method comprises the steps of:

• constructing a container with a number of partially reflective side walls arranged to define a light exit opening;
• and
• arranging a number of light-emitting diodes in the container to emit light of a first color through the light exit opening during an on-state of the lighting unit;
• wherein the material properties of the container side walls are chosen to impart a second non-white color to the container side walls, and
• absorb light in at least one specific region of the visible spectrum such that light of the non-white second color exits the lighting unit through the light exit opening during an off-state of the lighting unit,
• wherein the number of light-emitting diodes comprises a plurality of red light-emitting diodes;
• and
• wherein the material properties of the partially reflective container side walls are chosen to impart one of:
• a green color to the container side walls and to absorb light of a first specific region of the visible spectrum in a wavelength range of 380-480 nm;
• and to absorb light of a second specific region of the visible spectrum in a wavelength range of 540-630 nm;
• a yellow color to the container side walls and to absorb light of a specific region of the visible spectrum in a wavelength range of 400-520 nm;
• or
• a blue color to the container side walls and to absorb light of a specific region of the visible spectrum in a wavelength range of 550 nm-640 nm.