The best description of the relationship between colonists and the Delaware Indians in Pennsylvania during the 1680s is: The two groups were at peace after signing treaties based on trust.
In this period, especially under William Penn's leadership, there was an emphasis on negotiating and forming peaceful relationships with Native Americans, including the Delaware Indians, through treaties and agreements. However, it is important to note that tensions and conflicts did arise later as more settlers moved in and land became a significant issue, but initially, the focus was on coexistence and trust.