Nope. It hurts them. Minorities tend to be concentrated in large states. Smaller states are more likely to be ethnically homogeneous. Since small states are equal in power to large states in that they all get only two additional votes in the EC, the power of the large states is diminished a bit, and with that, the power of minority voters is diminished.
Actually, this analysis depends on whether my understanding of the EC is correct. I’m thinking that each state gets one EC vote for every member of congress they have.
For example, states like Montana and Alaska and Vermont, which all have only one congressman, have two senators and thus three votes apiece in the EC. Since those states are mostly all white, they will send their states in the direction the white voters want, with no influence from minority voters. Since each state is equal in the final voting, the power of large states (with minority voters) is diminished compared to the power of small states (with no minority voters) in the final election.