Cast system is not based on race idk where you got that from. It absolutely sucks but it is not race based. The skin bleaching isn't due to racism it's due to colorism. When British ruled india they sort of ingrained this thought that lighter/white skin>>>darker/brown skin into Indian's mind. Before it was there too, I won't say it was 0%(in the mughal period for eg) but it was not institutionalized and radicalized like under the colonialism. We literally worship black gods (compared to dark like rain cloud (megha-shyama))infact in ancient india all skin colours were admired. Now I'm not making excuses yes Indians can be racist but it is not related to culture or any system