What does Boo Radley really look like?

From the text:

I looked from his hands to his sand-stained khaki pants; my eyes traveled up his thin frame to his torn denim shirt. His face was as white as his hands, but for a shadow on his jutting chin. His cheeks were thin to hollowness; his mouth was wide; there were shallow, almost delicate indentations at his temples, and his gray eyes were so colorless I thought he was blind. His hair was dead and thin, almost feathery on top of his head.