What is the reason why lacquerware fades?

It's normal for lacquerware to fade, but it's just the length of time. Then we have to talk about the color of lacquerware. There are two colors: organic and inorganic. The brighter the color (such as bright red, yellow, green and blue), the faster it fades. On the contrary, the darker the inorganic color (such as black, brown and gray), the slower the fading.