The meaning of the scarlet letter changes overtime, at first it stands for adultry, then, it turns to able.
The symbol of the prison is a physical and physiological symbol. It is a physical place in the town (in a town a jail and a cemetary are built first) and physiological because secrets are kept and trapped in, waiting to be said.
The scaffold symbolizes sin and shame and is eventually the sight of ultimate redemption. It begins with public shaming of hester prynne and ends with salvation where Dimmesdale lets out his secret
Nature is the opposite of puritanism. It is a place you can go to reveal your thoughts. Puritanism is very dull and boring.
Sunlight is a symbol of truth and happiness, whenever the sun is out the mood is happier and there is less puritanism being showed.
Color is a very important symbol. It indicates character traits, shows mood and tone, and is all around. The puritans wear dull and bland colors, but Hester and Pearl wear bright colors.