This looks like a female or immature Painted Bunting to me. The bill looks to small for a tanager. Also, there is a fair bit of black along the bottom of the wing, which should help eliminate Summer Tanager. However, the black does not seem to extend into the secondaries much, which would help eliminate Scarlet Tanager. The back colour also seems a little to green for a Summer Tanager. Also, I find it unlikely that a tanager would visit a seed feeder.
Hope this helps.