In 2000 I was in a startup which used yellow and blue colours for all its graphic design (website, app, etc). For a big trade show (IBC Amsterdam) someone thought it would be cool to give away M&Ms, but only in yellow and blue of course ! So we bought many bags of M&Ms, and sorted them out by hand... That wasn't a good use of our time, plus we had tons of red, brown and green M&Ms to eat while working and we were getting diabetic fast. So Marie called Mars to ask if it was possible to buy only yellow and blue M&Ms for our trade show. And you know what happened? Mars sent us a huge bag of each colour for free !

In the following years, they made it possible to order custom M&Ms (for a price...) and how you can even have your logo on them.