In every garden there are varying degrees of shade. There is the deep shade where serious woodland-type plants are the only thing that will grow. And then there is partial shade. Bliss: you can grow plants with flowers that will give colour and delight in those dark corners. Be careful: you do need a few hours of sunlight, but nothing like direct, full sun over the day.
Here are some of the nicest partial-shade perennials. They spread rapidly, so you may have to do some serious ripping out after a few years.