Short, all season tree for small garden

Attached is my small backyard garden. the Japanese maple is not doing well, as you can see. can u suggest a few options for a nice all seasons blue evergreen or some tree that is colorful and there form spring…

Narrow growing evergreen *

Please recommend an evergreen that will grow less than 4 feet wide and 10 feet tall. Upright columnar yew? Faces east and will have about 6 hours of sunlight. Pickering Ontario location. To be planted beside a porch.…