Why Red Hats?

My mother is considering joining the Red Hats and we were wondering when and why they wear the color?

The Red Hat Society is a social group of ladies that are over the age of 50 and come together for activities and meetings. There is a Queen of each chapter and defined rules of the organization. The organization is designed to give middle age and beyond women a place to embrace their age and life. The red hat and purple clothing are associated with the founder’s birthday gift to a friend and a poem that went along with that gift. Though red hats are the normal attire, in combination with purple clothing, I have it on good authority that a birthday girl may wear a purple hat to distinguish her from the rest of the group. Ladies under the age of 50 that wish to join the organization are known as pink hatters and wear the color accordingly.