They're all mixed breed birds. The first one has something barred in the ancestry, but I honestly don't think he's a first generation mix of something purebred barred. He's way lighter and more diluted looking than my first generation barred mixes.
Second bird--something red mixed with something white. Not sure where the pea comb comes from?
Third bird I would guess has some Orpington in the background, with the size and white legs. But he also looks to have a pea comb?