Peppers benefit from small supports or staking as they often produce abundant and heavy fruit.
However, if you allow peppers to remain on the plant another few weeks, they will eventually turn (or mature) to red, yellow, orange, or even purple.  Transplants of bell peppers are planted outdoors starting in mid-May at 1.5 to 2 feet apart in rows.  Peppers benefit from small supports or staking as they often produce abundant and heavy fruit.  For more information on growing peppers, check out Peppers (link) from ISU Extension and Outreach.