The Brits do a lot with 4 season color. There are some willows with bare red stems, for example. The other thing I've see done is lights. Architectural trees and branches lit up with colored lights. (It helps if you have snow).

Annuals tend to give you longer lasting color than perennials, if you are willing to replant every spring. Ornamental kales will give you winter 'flowers.'

I note that you have a fair amount of boring hedge. It's not needed for privacy, if it's not needed for noise reduction, I'd consider replacing it with something more interesting. For example, if you get large grasses, you can have the decorative effect all winter.

Go to the library and load up on gardening books for inspiration.

Yes , I see a lot of potential in your backyard , and sigrida is correct get rid of that Hedge , and in the water feature put some Coloured carps for a lively feel , and you can feed the fish daily its fun to watch them feeding , on my recent trip to Thailand I saw fishes being bottle fed in a Pond .

http://www.amazon.com/Garden365-Water-Garden-Latte/dp/B006F63TIS/ref=pd_sim_sbs_lg_5

Hi Sigrida-
First let me say your patio is lovely. We are so fortunate with the variety of plants we can grow here. Looks like your exposure is part sun/shade, so I will base my advice on that. The hedge is healthy and provides some much needed "psychological" separation from your neighbor. Unless you hate it, I would leave it, but as another poster mentioned, trim it up from the bottom just a bit, and add some color. Check out Japanese Forest Grass (hakonechloa macra). The variegeated variety would really "pop".You could also mix them with vibrant purple and pink impatiens in the summer for some great color! I like the idea of your colored pot/mini fountain. Much less maintenance than larger ones that can get clogged up and need unclogging a few times per year. You also have room for more groupings of containers with a mix of perennials and annuals for year round interest. Heuchera in dozens of different colors from lime green to dark burgundy, autumn ferns, black mondo grass, adding in spring: coleus, wax begonias and impatiens-Beautiful! Stacy Heintz, Landscape Designer

Please see the fun pots-fountain built for small spaces - great one for Seattle weather https://www.houzz.com/photos/ygp-show-2012-mediterranean-exterior-portland-phvw-vp~796536

The plant with the red stems is probably dogwood. You will have to look after it carefully as it can get quite big!

Wonderful suggestions above. I'll only add that you could consider a colorful wall fountain and plantings below it for seasonal interest. The West Seattle Nursery has some really nice ceramic fountains if you choose to go that route. They're also a relatively easy DIY project. Check out Sunset for step-by-step instructions. Beautiful area. Enjoy!

http://www.sunset.com/garden/backyard-projects/great-ideas-fountains-00400000045254/

Thanks everyone for the great suggestions! I'm really excited about this project now. Right now, I'm focused on the middle section, so the bushes will stay. I like them anyway, but really like the idea to put in some flowers beneath to add more interest. The flowers would have to grow up high though. The leaves on the bushes actually start about a foot from the ground. They are in a big long deep planter with the front part coming up to just underneath where the leaves start.

you can also get wall fountains at www.VillaAndMissionImports.com