Final answer:
Lady Macbeth says, 'I shame to wear a heart so white' to Macbeth, criticizing his fearfulness after the murder of King Duncan in 'Macbeth' Act 2, Scene 2.
Step-by-step explanation:
In Act 2, Scene 2 of Macbeth, the line "I shame to wear a heart so white" is said by Lady Macbeth to Macbeth. This is after Macbeth has murdered King Duncan and is expressing his guilt and fear. Lady Macbeth chides him for his cowardice, indicating that while their hands may be equally bloody, she refuses to have the fear (a white heart) that Macbeth is exhibiting.