Peanut M&M's were introduced in 1954, and at first they were all one color - tan! They got introduced the same time the famous "Melts in your mouth, not in your hand." slogan came out. Later on in 1960 more colors were added that included red, green and yellow. This genius recipe of milk chocolate covered peanuts in a colorful candy shell is one of our best selling candies. Who doesn't love M&M's! These are 3.1 oz theater size boxes.