If you love vibrant colors I would choose a bright yellow or orange day lily, easy care perennials and can take afternoon sun. Anchor it with a couple evergreen shrubs for structure and winter interest, maybe blue rug juniper with a mounding or conical yellow green. Red clematis would look sweet climbing the light post, depends on your garden style.

I like the stones you have there, you could play those up with your plant picks to go alongside those, maybe some Thyme or some low flowing grass? I'm thinking something like Japanese Forest Grass.