Agreed, those colors aren't very good and you might be right about the mask. I shoved that through vuescan very quickly and was completely amazed at the lack of grain. Didn't try to make any color correction at all.
I printed the same negative this evening on some Kodak Edge and it looks great! No red in the shadows. Also tried to print on some older Supra Endura and that didn't work so well. But it's some old hand-me-down paper so who knows. The Edge is fairly new and I would imagine that Kodak has set the film up for their current papers.