Clearly, Hwang's playwright-within-the-play has been on a colorful journey, full of characters that amuse, anger and move him. Hwang's genius here is his ability to spin his real life into a fascinatingly entertaining work using all these events and characters. He is artful in balancing the lighthearted with the sardonic and the dramatic, the result being a colorful portrait. The flier for "Yellow Face" shows…