Did you know there are more than 7,000 varieties of rice? If you will insist on buying some of the 6,997 varieties that are not available at the supermarket, you might consider picking up Beth Hensperger's new book, The Ultimate Rice Cooker Cookbook (Canada, UK).
Yes, Hensperger, better known, perhaps, for The Bread Bible (Canada, UK), Bread for All Seasons (Canada, UK), and The Bread Lover's Bread Machine Cookbook (Canada, UK), has made the leap to rice, and her new book is as comprehensive and useful as her other works.
Black or purple rice is unmilled, leaving a dark husk in place, which colors the grains when they cook. There are hundreds of varieties of black rice in Asia, and they are particularly popular in Burma, Thailand, Malaysia, Singapore, Indonesia, and the Philippines. They are often used in desserts, because they go so well with sugar.
Because they are unhulled, black and purple varieties of rice are classified as brown rice (which only adds to the confusion you face), but therefore are cooked a little differently than varieties of white rice. Hensperger says most rice cookers were not engineered with brown rice in mind, but will turn out a lovely brown rice if you experiment a little. Because the hull is intact, the grains take longer to cook and need a bit more water. If you can soak the rice in water for an hour before you start cooking it, the result will be more tender. She also says you should use a quarter of a cup more water than the instructions call for. But because you must use more water, be careful not to overload your rice cooker, as the result can be a messy boilover.
Here is a simple dessert recipe - Black Sticky Rice with Sesame Seeds - from Charmaine Solomon that mixes purple rice with sesame seeds. The instructions assume you do not have a rice cooker, but as a proud rice-cooker owner you can skip to the end.