Silverton Boar Dogs
Sorry, but reg. Corriente cows should have no white at all, those look like longhorn crosses to me.
Not sure where your information comes from, but here is some that contradicts what you are stating.
According to the North American Corriente Association
http://www.corrientecattle.org/id8.htmlAny color is acceptable except solid white with absolutely no pigmentation whatsoever.
Here are the judging guidelines for Corriente Cattle
http://www.corrientecattle.org/id7.html