For color, try impatiens
The large flowers of New Guinea impatiens brighten a lightly shaded spot. Here, a pure white impatiens (repeated in the companion pot) is accented with the frilly burgundy and pink leaves of 'hilo holiday' rex begonias, part of the Great American Cities series of rex begonias. The feltlike, gray-green leaves of 'Silver shield' plectranthus argentatus (also called silver plectranthus) grow on long stems that will trail downward. The neutral color of the plectranthus pairs well with many other plants.
All three of these do well with bright shade (morning sun is OK). Keep the soil evenly moist but not overwatered. Fertilize once or twice a month.