She came from the splash rooster, so that means he is carrying recessive white if she really is white. That also means at least one hen is carrying it. If I understand correctly, that means she now has 2 copies of the white gene, and if bred back to the splash with one recessive, the odds of them producing more white goes up
So I have a chance if my black/blue roosters. If they came from a splash breeding that had recessive white gene that produced them. They could then breed with one of my splash hens and if she also has recessive white gene could produce white. Wow I confussed myself!