The color of porcelain is very sensible. Sometimes one porcelain ware could present different color upon the naked eyes under different light conditions. Here we show one photo of turquoise brush washer from 18^th century. On different light condition, the washer shows rather different color.

There are different systems to define color, e.g. RGB, CMKY, HLB, and HSV. For Chinese porcelain, it is quite often to use the object around our living environment to define the color such as lake-water-green, sky-blue, and ox-blood red.

Even just for one color on porcelain, it could be very variable. One example is on one famille-rose porcelain ware, the pink color could show broad range from very deep to light.  So, using one number to define the color is almost impossible or inaccurate. Here we use HSV system to describe the color on the porcelain as the value range of Hue, Saturation, and Luminosity Value.

First, we use color sensor directly on the surface of the porcelain to exclude the light influence from resources out around. After getting the color photo, we use Python to analyze the composition of the color.