Hostas love the shade but are not evergreen.
In my shade garden I have container which has snowdrops for late winter interest (and the pretty white flowers); a hosta with white edges to the leaves, which has pretty summer purple flowers; but for year round evergreen element I have a vinca major which drapes down the side of the container. It has a white flower, but the most usual colour for a vinca flower is on the purple scale.
Have you considered Azalea? It is an acid loving plant and would need ericaceous compost and is just coming into flower around now but the leaves/plant is evergreen. I have two at the moment, a delicate pink one and a white one, both in full bud and the first flower has appeared on my pink one.
You could go the fern route to add a different textured leaf.
Another option (but not evergreen) could be a "Bleeding Heart" (dicentra - although I think it has been reclassified as something else). Very pretty but not evergreen nor fragrant.
Personally, I would be looking at a hosta for Spring - Autumn interest with its lush leaves, under-planted with snowdrops for late Winter interest, with a vinca to trail over the edge and give year round interest. All are happy shielded from the heat of a drying sun.