Bill~
Glad you like the Redhead. As it turns out, the color I used was by Valspar (Lowe's). It's the color we painted our summer camp up on Lake Champ[lain: Lyndhurst Rich Brown (1006-7A). (The name is a bit misleading - it's a dark, "barn red".) I painted the whole head with it - then brightened up the cheeks with some Burnt Sienna (from the tube). BTW: The Lyndhurst is good for Drake Mallard breasts, too.
To my eye, a Redhead has a head color that is a bit less "rusty" than a Canvasback. So, I like something that has a hint of Rose in it - but with the Rustier accents on the cheeks to add to depth.
If you want to use Behr, I would look at PPU1-14 (Formal Maroon) as the base color with PPU-17 (Morocco Red) for accents. This is certainly not an exact science, especially with seasonal plumage variations AND the different decoy surface textures. These heads were painted over my sawdust+epoxy "skin" (and the bodies were over burlap+mastic).
Hope this helps,
SJS