I haven't seen a Marans that is Isabella/Isobel/Isabelle but I did recently learn about that type of coloring a little bit. It is basically the lavender gene used to dilute a patterned bird (usually) like these Isabella Leghorns and Brahmas http://www.leghorn.nl/artikelen/Isabel patrijs-UK.pdf I am on a waiting list to see about purchasing some her in the US, though I don't know that I will be able to afford it, LOL! http://backwoodspoultryfarm.com/Breeds.html There are also Lavender Leghorns http://oldorchardfarms.weebly.com/leghorns.htmlEver hear of 'Isabella" Marans?