It is most likely a Stonechat. Their upper body (wings, head, and tail) are most often black, but the underside is white, with the exception of the breast.
If you have a pic of the bird you are wondering about you can do a net search on it and find hat kind of bird it is you can also take the picture into your vet and show them and they should be able to tell you what kind.
Some zebra finches are bred in white with an orange belly, but finches are small. Some parrots and cockatoos are also bred to have white feathers, so it could be one of these.
