Nichia released a new COB LED series featuring tunable color. With the new color tunable LEDs, color temperatures could be adjusted according to natural biological rhythms for human centric lighting applications. On existing tunable light fixtures, the method to select and balance color temperatures is to mount multiple LED packages onto one board. This approach provides flexibility in the design but increases the complexity to properly mix the color of each LED. Moreover, it is difficult to develop color tunable fixtures with narrow beam patterns and harmonized color....