Unusual Bird: White-headed house finch

I’ve observed red, orange, and yellow house finches at my thistle feeder. New this year, a white-headed house finch. No white on the breast where the red would be on a typical male house finch, nor on the back or rump. So it seems to be a female with white on the head, which is also strange. I don’t know that this would be classified leucistic because it is not completely white, but I will classify it that way and look forward to feedback.