Sorrel/chestnut?

I grew up calling horses with reddish/brown coats, manes, and tails chestnuts. But I recently noticed the horses below (photos) being referred to as sorrels. Sorrel, to me, conjures up thoughts of cowponies on ranches and wild mustangs (a very nice thought), and books by Will James and such. Wikipedia seems to think sorrels and chestnuts are, pretty much, interchangeable. What would you call this family (foal, sire in center, mare on right)?: http://www.barbaralivingston.com/gallery/album102/OI5I7074" onclick="window.open(this.href);return false; Mare up close: http://www.barbaralivingston.com/gallery/album102/BDL_8967" onclick="window.open(this.href);return false; Mare full body: http://www.barbaralivingston.com/gallery/album102/BDL_8942" onclick="window.open(this.href);return false; I don't see anything else obvious going on, unless the lighter mane should be 'telling me' something. ? Thanks!