The first victims of redlining were the homeowners. Want to sell? Good luck getting a decent price in the red lines. Want to remortgage? Sorry, redlined. Want a loan? Didn't you notice you're redlined?
You seem to have the idea that poor whites could somehow afford higher prices because they're white. Nope. Want a loan to buy a cheap house that's redlined, white person? No discount for whiteness, pal.
So, yes, redlining very much affected people of all races who would've been able to borrow at better rates than anyone could get in a red zone, and it affected everyone of all races who would want to sell. The only people who benefited were the banks and the developers who had the cash to grab cheap property from desperate people of all races. You know the French Quarter was a cash cow for developers, and because New Orleans had a significant black bourgeoisie, it's safe to assume many of them were black.
I fully agree that redlining during Jim Crow limited possibilities for black people. But I haven't seen anyone try to do the math to figure out by how much. I trust we can agree that the failure to provide 40 acres and a mule had a much greater effect on black generational poverty.