Danni,
There isn't a whole lot different about the fireball. It's kind of like a pastel we can use for comparison. There isn't a whole lot wrong with the Co-Dominant form. But as you know, 2 pastels bred together makes a Super Pastel.
If you breed 2 fireballs together, you get luecistics. They look a bit different then normals, but the full dominant form defenitely lets you know they are something.
Hope that helped a bit... On.... oh I can't remember the name. Maybe it's
www.constrictors.com or something like that they have fireballs, and a page about them in the For Sale section...