Dark solid colored snakes and misshapen heads?

Just speculation, but is it me or is it that a lot of the one color dark snakes have oddly shaped heads? Like duckbills with super cinny's, and the weird elongated heads of sumas, and the super motley boas...

Anybody else notice this? Does anybody know why?

I don't know why.... But I know that a lot of the all white Boa's have misshapen heads as well.... Maybe its not so much the color but more the gene that suppresses the pattern of the snake?

Its just a thought, I'd be curious to know what people that know what they're talking about have to say. :P