I know; there are some MIGHTY dark ones; but i'm guessing
1) Indians make up such a small part of the population, versus Blacks who are the 3rd largest group, that there aren't enough of them for their complaints to warrant any attention
2) Most of the Indians in the U.S. are easily distinguishable from Blacks, and have several features that people say are Caucasoid--hair texture, skull shape, etc
3) Most of the Indians in the U.S. aren't poor, and since the poor minorities face the most racism, as a member of the elite that made it the U.S. they are immune to most of it
4) They do not share the same history with Whites that Blacks do.
EDIT: For those who say it because Indians just come here to work & not play the victime; Africans come to the U.S. much the same Indians do, and work even harder [as evidenced as in their ranking as the highest educated group , percentage wise, in the U.S.] yet even they complain about it