A system including a base portion, which includes first and second sets of light emitting diodes (LEDs) to emit blue light having first and second wavelengths in first and second wavelength ranges in a spectrum of blue light, a glass layer arranged at a second predetermined distance from the base portion, and a plurality of coatings of first and second phosphors having a predetermined length arranged in an alternating pattern on a surface of the glass layer facing toward the LEDs. The LEDs of the first and second sets are arranged on the base portion in an alternating pattern and are separated from each other by a first predetermined distance. Centers of the coatings of the first and second phosphors respectively align with centers of corresponding LEDs in the first and second sets.