What color is the changed oil that is normal?

It is normal that the engine oil is black, because the function of the engine oil is to lubricate the parts in the engine, and the products of combustion inside are dark gelatinous substances, so the engine oil will change color from the first day of use when injected into the engine, but the life of the bad engine oil is shorter. Like the GT engine oil I used, the content of PAO base oil is also relatively high, so the performance is very good, and the maintenance cycle is particularly long, reaching about 15000 km!