"Grace has 16 jellybeans in her pocket. She has 8 red ones, 4 green ones, and 4 blue ones. What is the minimum number of jellybeans she must take out of her pocket to ensure that she has one of each color?"

I thought, "Ok, there are 8 red jellybeans, but only 4 green and 4 blue jellybeans...so that means that there has to be 4 red and 4 green and 4 blue jellybeans that are taken out of her pocket to reach the minimum number of jellybeans to ensure that she has one of each color" in reality, the answer for this problem is 13. Thirteen?? Where the hell did that number come from??? I just don't understand why this is the answer. Perhaps someone could enlighten me.(Headbang)