After the Aryans occupied India, the system formulated for the convenience of ruling Indians divided the local Indians into low castes, stipulating that they could only live in southern India, while Aryans were divided into high castes and lived in northern India.
The noblest Brahmins are pure Aryans, because they are forbidden to marry Indians. The Indians of the following two castes will have some indigenous Indian ancestry to some extent. But they still look white.
The origin of caste system
Around 1500 BC, the Aryans conquered the Indian Peninsula and established a light-skinned caste system in order to maintain their long-term rule. They invented a legendary story, saying that Brahma, the creator, turned his head into Brahma, his upper limbs and body into Khshatriya, his legs into Vedas and his feet into sudra.
Priests belong to Brahmins, warriors belong to Khrushchev, and agricultural, commercial and handicraft groups belong to Vedas, so the conquered indigenous people became sudra with low status.
Babies born to men of any other caste in sudra are untouchables. Over the past 3,000 years, they have also produced an extremely large group, which, together with sudra, has occupied more than 80% of the population of modern India and become the bottom of the pyramid structure.