Where have all the green potato chips gone?

I started wondering about this after seeing an Arthur episode in which D.W. thinks she's going to die from eating a green potato chip. I remember seeing green ones all the time when I was a child, then they just. . . disappeared. I supposed that quality control has improved that much, or that the green ones had been genetically modified away. I never really missed them; they were a little disturbing and tasted a little funny, too. But today, eating some McDonald's french fries, I saw it--a fry with a GREEN TIP! Aaaaaaaaaah!