Looks similar to the YB calico I produced this year. I actually produced three of them. One is really extreme and the others are very low white and you can barely tell they are calicos. I have produced lots of Ybs and there is definitely more going on with this guy. I am not saying it is Calico,but similar. There could be cinny or het red there also. Keep it for sure and prove it out. What do the others and the parents look like???