Steven Berkoff claims restricting the Shakespearean role to black actors is 'racism in reverse'. But colourblind casting does happen " and it benefits minority actorsFor every action, there is a reaction. First, a long and pretty stellar list of black actors observe that they need to leave the country to stand a chance of being cast in roles suited to their talents. Off went David Harewood, Lennie James, Marianne Jea…