With the emergence of automotive-grade RGB single-package LEDs, the design of RGB ambient lighting has become more and more flexible, and it saves limited valuable space in the car than using three automotive-grade LED particles with different colors of R, G and B. However, due to the high requirements for color and brightness consistency of automotive interior backlighting and its ambient lighting, color consistency control becomes a difficult application point for RGB ambient lighting. The RGB dimming calibration system we developed can solve the problem of RGB LED Optical-Color inconsistency.