Princess, if you read the thread title as one sentence and Urban's post as the 2nd, she does know that mille fleur is a colour, and is asking about blue mille fleur in the d'uccle breed.
I've never even heard of the Blues either, but I ordered some from Ideal. They are supposed to be just like the Blacks, but with blue replacing the black... I don't know. I've never seen a picture of one.
I'll check out the link to Cackle. I think I've seen the ones you're talking about, but I'll look anyways just to be sure