AFAIK "yellow head" is a bloodline of albino that originated at VPI.

http://www.vpi.com/2008/04/07/04_07_08

... I was told that my male descends from that bloodline, though oddly enough he doesn't have a yellow head.



My guess would be that it's genetic in the sense that if you select for albinos with yellow heads, you'll continue to get albinos with yellow heads, but if you mix in other bloodlines (as probably happened with my guy), you start to get more "normal" looking albinos. (Ie, it's a trait that has to be line bred/selected for, not a single-gene trait.)