I photographed this yellow bird two days prior to capturing the reddish Purple Finch picture. The similarities gave me reason to enlist birding friends with more experience to help with the differences between Purple and House Finches. The bird identification texts I use and everyone else who has had read them suggested that a Yellow Purple Finch, while possible, is a rare event.
Art Swalell, an owner of Bird Photography a community on Google+ asked an unnamed ornithologist about this birds ID. His response gives a number of useful characteristics that differentiate Purple Finches and House Finches. "I feel confident that the xanthochroic finch is a Purple. If you replaced the yellow with raspberry, the color pattern would be perfect for a Purple and wrong for a House. Among several other examples, notice the pale outline of the auriculars (including a broad post-superciliary), reminiscent of the facial pattern of a female Purple, and the "blurry" yellowish flank streaks, unlike a House Finch's thinner - and brown - flank streaks. The bill shape is also just right for Purple and wrong for House: notice the straight culmen (downcurved in House), sharp tip (upper mandible typically protrudes slightly past lower in House), and base of lower mandible thicker than base of upper (opposite in House). The tail is also short and notched, another character good for Purple and wrong for House."
