May I suggest a cap of your pavers on the wall and the a slightly darker gray that relates to the privacy fence beyond? That way horizontal surfaces and vertical surfaces show similarities and blends/blurs the separations?

As the appearance of the garden has a modernist style with the straight lines and concrete furniture how about a Mondrian influence and add a bold strip of blue? It is a pond and with the right shade it could look really relaxed and contemporary. My daughter's suggestion is a chalky lilac!

You need light and bright. Being rented is tough. First change out the drapes with to the floor length. Cream with a horizontal stripe of brown to match or furniture. This will 1. get rid of the horrid things hanging there 2. pull the initial visual to that wall instead of the floor. Tall and high colors ( mango, aqua, yellow) decorations on your mantel with shorter cream and brown items. Then a large square table in the middle, painted distressed cream, with high color items setting on it. DIY project or Ikea. Green is the number one calming color, just don't let it put you to sleep. :)

Teal? Just a thought sometimes I think it's smart to match or atleast go with the curtains you'd see in the window