My hands are of your colour; but I shame
To wear a heart so white.

– William Shakespeare

Macbeth, Act 2, Scene 2. The audience doesn’t see the murder of King Duncan on stage, but Shakespeare employs dramatic genius to convey the horror of the murder to them. He cleverly does this through the use of blood. First Macbeth’s hands are covered in blood. In this passage Lady Macbeth’s are also smeared with it, having covered the faces of Duncan’s servants with blood to make them appear guilty. In contrast to her husband, she shows no remorse or guilt over the spilling of Duncan’s blood. Using a metaphor, she tells Macbeth that she would be ashamed to have a heart as pure as his.