Hah, Patz' explanation for beans was that actually, most people get really good luck. It's a one percent chance that you're gonna get albino. That's one in a hundred. Eighteen beans without a rare color isn't exactly bad luck. It's just not insanely good. P:
Sepia and cream are basically the naturals of beans. Everyone who uses a bean has a pretty decent chance of getting that repetitive sepia, cream, sepia, cream cycle. They're the two most common colors, and it's usually gonna pick the most common color available.