I have a blue showgirl, a black partridge (though it is a very bad one and may actually be a black with gold leakage) and an Isabel (again, not great color quality and may be better described as a brassy yet very pale self blue i'm am thinking a black rooster would be best. though i am not familiar with how the isabelIsabel coloring is created. Is it similar to self blue, ie covering black or is it it's own color completely. I've searched online but found no clear info. Any advice, suggestions would be appreciated.