Over at Brown Pundits Zach Latif brings up the point that the Indian bias for light skin may date back to the Aryans. And it does seem that such a bias manifests in the earliest texts. But as someone not able to read the original languages I can ascertain the arguments as the import of these passages only at a remove, second and third hand. Some scholars have suggested that the racialized interpretations of the treatments of the interactions between the Aryans and the natives of India are just a look at the past through the lens of the present. They are argue that color terms in the Vedas are metaphors. In contrast, there are others who seem to be arguing for a more straightforward and "literal" reading of the source text. As a non-philologist there's little I can add. But I didn't dismiss those who argued for a metaphorical reading because I know from the literature in the area of Biblical scholarship that straightforward and "literal" readings are quite often deceptive and require their own interpretation (it is difficult to transfer idioms and metaphors properly across languages, and the translators are tempted to render them in the most congenial manner to their own broader theses).
To be frank the information being uncovered by Zack and others makes me think that there was a racial aspect to these conflicts; that the literal reading has some truth. The tribal folk of India are genetically distinct from the caste populations, especially the higher castes. Though all South Asians are a mix to varying degrees of an exogenous West Eurasian element and a South Eurasian indigenous component, the non-Austro-Asiatic tribal populations seem to be a relatively simple combination. The genetic complexity of the structure of other groups suggests to me that there were several later West Eurasian intrusions after the arrival of the "Ancestral North Indians" (ANI), and their hybridization event with the "Ancestral South Indians" (ASI). Racialized language in the older Hindu scriptures may then be conceived of as a conflict between the latest arrivals and the older long established groups which were a stabilized ANI-ASI compound.
One can imagine that this process recapitulated itself in the late medieval and early modern period with the arrival of the Muslims. The ruling Islamic elites who were of Persian and Turk stock viewed the native Hindus through a racialized lens, and were at pains (and to some extent still are!) to distinguish between Muslims of foreign provenance who were "white" and converts from the native populations who were "black." The physical differences are evident when you compare the Emperor Akbar with his grandson Shah Jahan, whose other three grandparents were Rajputs.