Finches are frequent winter visitors to our bird feeders in the Ozarks. The American gold finch is readily identifiable by its yellow color, even though it hasn't yet brightened its feathers for the mating season. Another visitor, the house finch, is commonly mistakenly identified as a Purple finch. The purple finch has a brighter color to its body, described by Roger Tory Peterson as a “sparrow dipped in raspberry juice.”
House finches are much more commonly seen in Missouri than purple finches. This somewhat more drab cousin to the purple finch has much less color on its body. (See allaboutbirds.org) It is a relative newcomer to the Ozarks. They were native to the West Coast, where they were collected, then sold as popular house pets on the East Coast where they were marketed as "Hollywood Finches." Fearing the enforcement of the Migratory Bird Treaty Act of 1918, which included prohibiting the sale and keeping of these wild birds, a New York City pet shop and others released their finches in 1940. Although few in number, they have thrived and out competed our purple finches, but at a price. They are susceptible to Mycoplasma gallisepticum, or house finch conjunctivitis, a purely avian disease. This is thought to be the product of inbreeding and they may acquire resistance with time.
The whole story is available in Francis Skalicky's News-Leader article, with details at Wikipedia.