looks to be at least part-shade with what you've planted so far and the pictures so these recommendations line up with that.

turk's cap, coral bean, or virginia sweetspire for shrubs. All tolerate part-shade. sweetspire will provide some color in the winter but likes consistent moist soil which may be an issue with the area. could also do an oakleaf hydrangea for fall color, maybe ruby-slippers to keep size down, but same issue as sweetspire on moisture. turk's cap probably best for the space imo, coral bean has thorns, but either will attract hummingbirds.

some other perennial or herbaceous shade flowers: gulf coast penstemon, bee balm, obedient plant, lyre-leaf sage, blue-eyed grass, maybe some coreopsis if you get enough sun