July 12 is Different Color Eyes Day, yes there is such a day. Having 2 different color eyes is more common in animals than in humans. The condition is called Heterochromia and effects about 200,000 people in the USA.
Famous people who have Heterochromia: David Bowie, Jane Seymour, and Christopher Walken. Kieger Sutherland, Dan Aykroyd, Kate Bosworth, MilaKunis, Michael Flatley, Alexander the Great.
If you want to know what eye color your kids will have- check out Genetics.