In the UK they are called booted bantams as well, but the colour I think is called buff white millefleur and is in our standards.
I have no clue, thats just what it is called.
No, this pattern is Mille Fleur with dominant white added. The dominant white changes the black spots to white and lightens the gold color. Mottling will add the black band with or without columbian, it's not related.