As a subject matter expert on confectionery products, I can tell you that the most common color of M&M's has varied over the years due to changes in the mix. However, traditionally, the color brown has been the most prevalent in a standard bag of M&M's, primarily because it represents the original color of the candy when it was first introduced in 1941. The brown M&M's are peanut flavored, which is also one of the most popular flavors among consumers.

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After wondering about it a little more, I checked out M&M's web site. According to it, each package of Milk Chocolate M&M's should contain 24% blue, 14% brown, 16% green, 20% orange, 13% red, and 14% yellow M&M's.read more >>