You can stay in Australia for several years.

I'm sorry, as far as I know, in Australia, there is no rule about "black year can have identity"

If you enter and live in Australia illegally, you will not be able to obtain legal status in Australia. In Australian immigration law, there is a strict definition of black people, and the punishment measures for black people are also clearly defined. Generally speaking, all illegal immigrants have reason to be suspected of coming to Australia illegally. Once found, they will be detained by the relevant authorities until they leave Australia, are deported or get a new valid Australian visa.

If you want to know more about obtaining legal status in Australia, I suggest you consult the Australian Immigration Bureau or a professional immigration lawyer.