The creator of the project, book artist Emily Martin, says:
My sister Martha inadvertently set this project in motion by giving me a set of the Pantone® postcards as a Valentine’s Day gift.
I put out a call on Facebook for volunteers to receive a postcard randomly selected for them and then to consider, reflect on, in some way react to the color they had been given and do something to the postcard in response to that consideration, reflection or reaction and put it back in the mail to me. The only restriction is that the postcard be able to pass through the US Postal Service. In a frantic 17 hours, some of which I was asleep, all the postcards were claimed and mailed out to 25 states and the District of Columbia in the US, Canada, Chile, Italy and the UK.