Purchasing single color m&m's can be expensive. Instead, I purchased a large bag from Costco and sorted the colors.
The problem with this method is that my fingers touched each one. I washed my hands well before doing this...but it made me realize I should probably eat less of anything that is unwrapped.
Thinking that the bag would have close to equal proportions, I was a bit surprised that after I sorted there was a big difference.
After sorting, I decided to weigh the candies. I put all the candies in a plastic bag, which I weighed, then I subtracted the bag weight from the total weight.
Yellow: 218 grams
Green: 351 grams
Blue: 372 grams
Brown: 230 grams
Orange: 335 grams
Red: 68 grams
I probably ate 8 candies or so while I was sorting, before I thought about weighing the candies.
I used the blue; wanted to use red too, but there weren't enough and I wasn't going to buy another bag. The rest of the candies will be eaten or used in cookies or other baked goods.
Lesson learned, if you want guaranteed colors, buy smaller bags during certain times of year (Valentine's Day = red, pink, white; Easter = pastels) or buy bulk colors directly from m&m's website.