Most businessmen speculate on the color of bian stone for profit. Sibin's genuine bian stone skin is black, and the effect of any color is the same, but you must buy the real bian stone. Most of the shops on the roadside and online buy fakes or defective products. Now, if you want to buy Bian Shi, you should read the words of the Drug Administration and the test report. Color is not the main thing.