That looks like a bird I've seen for the last 2 days that I wasn't sure about either. The only thing I could find that looked like a match was a female Purple Finch. I need to be sure because I'm wanting to report it to the Feeder Watch program I'm doing. Here are a couple of my photos.
I wonder where the guys are? I've had a few House Finch male and female but haven't seen anything that looks like the male PF. To me, the male PF and HF are the hardest to tell apart, except for some of the sparrows.