True.
The Indian government promised to do away with the caste system. And so they did but the ancient and pervasive idea of superior and inferior people stays with them.
One misconception is that the lowest caste, the untouchables, are not necessarily poor. Some of them are quite wealthy.
Conversely the Brahmin class (most superior) contains its very own share of bums, dumbos and wastrels.
It just so HAPPENS that the untouchable class, the lowest, is the darkest-skinned and the Brahmins, the by-nature-uppper-class are the lightest-skinned.
This is pretty much a universal. In just about every society in the world from Norway to Bengal to Lesotho, the ruling class is lighter skinned than the rest of the population. The preference for lighter skin is universal and does not relate to what we call race per se. If a very dark usurper kicks out the light skinned ruler and takes the throne he then marries off his children to the lighter skinned members of the society.
These things are true in all of the mostly Nero populations of the Caribbean and in Angola. Among the educated in every culture mom is apt to ask her son, about his new girlfriend, isn't she a little dark?