Which two colors make purple when mixed?

Blue and Red

Which actor portrays Professor Albus Dumbledore starting "Harry Potter and the Prisoner of Azkaban"? Which bird is known to collect shiny objects in nests? What's the main character's name in the original 'Half-Life' series? What is the password to the Gryffindor common room during Harry’s first year Christmas time? Which former NBA star became mayor of Sacramento after retiring?