This looked like a female house finch at first, but it’s definitely a male. And an adult, because immature males have the same plain browny stripes as females. Fun fact I just learned: plumage colour varies with diet, specifically with how much carotenoids they get. Red, orange or even bright yellow house finches are possible.

I’m surprised this one’s so different, since I would think it eats the same stuff as all the other finches. Maybe it’s just a bit of a mutant and can’t absorb carotenoids as well.