Tiny migrating yellow and Green Birds

The left one is a Connecticutt warbler and the right one is a common Yellowthroat bird. I saw something that was at most 3 inches long (about the size of a hummingbird today) in the Northern California Coastal forests where there are ferns, Pine trees and some Redwood trees. I had just watched "Epic" the movie and since there were 6 or 8 of them it was sort of like living the movie. My dogs seem to sense the magic of these birds too that obviously were traveling through migrating to somewhere else because I only see these types of birds as they migrate through in the Spring and fall usually. Like I said they were so tiny they were the size of hummingbirds. The colorations are right but I'm not sure either of these is the right species. They were tiny with green and yellow or gold on them.