We see a crown in a shape of three witches, which implies that Macbeth's mind was controlled by the witches by telling him his future, which may of seemed great in the beggining but soon became violent and bloody.
After MacBeth has killed King Duncan, he looks at the blood on his hand and wonders if he will ever be free of the stains of guilt. (Will all great Neptune’s ocean wash this blood/Clean from my hand? II ii 61). Blood becomes a repeated image, also symbolizing the guilt of killing and betraying.