I think that you need mostly white, but something in a print that incorporates your colors. Perhaps pillow slips or at least a mostly pea green painting/poster/wall-hanging that also has some brown, perhaps in the frame. You could also do a stencil on the pink wall using the green paint, some white, and some brown. How about a nice tree branch? You can also buy vinyl decals from Etsy or other places--not sure that you could get pea green, but brown and white should be available.

You have a nice geometric, somewhat masculine look going here. I would play that up. I don't think you need to change the wall or carpet color as they seem to be a nice neutral background. Are they cream? is the purple more plum? and is the blue more of a steel blue/gray? The furniture is chocolate brown? I love the striped pillow on the chair. I would layer a wool steel blue/gray area rug and then play up the blue/plum in the pillows. A wool plaid or blue gray herringbone in a couple of throw pillows (replace a few of the solid color pillows) could help to pull it all together. Kind of like the colors in the picture of this bag. Adding brown leather cording would be a great compliment on the pillows. (Not sure the area rug in front of the TV is adding anything)

I think your inclination toward rustic and distressed pieces is the right way to go. Consider a movable coffee table - I see 2 recliners that may necessitate some table shifting?- an area rug large enough to incorporate all the seating, rather than just a hearth rug, and enclosed storage for your electronics. If you can post shots of the room, other Houzers may have some more ideas.

This is a great space to work with. Since you have a good length, you can break the terrace into rooms.. with yew to divide the areas, or tall plants with shallow roots. Grow grass in curves and a pathway to lead visitors through the various rooms. Couple of ideas for garden 'rooms': Bamboo with golden stem or black stem as background, with charpai and 'moda' seating with cushions. A light under the foot of the bamboo, looking up will be alluring. Put up a trellis with fragrant climbers like jasmine and seating underneath on a part of the terrace which gets shade in the evening so you and your friends and family can relax. A dry garden with hardy plants like tall grass and Palm tree, pebbles on the ground to create the look. Plant a small flowering tree in one 'room' Add evocative lighting to create the mood in the evenings. As you can see there are many possibilities. Please ensure the ground is well protected from water seepage etc before you start planting. Also ensure the height of the periphery wall is taller for it to be safe for children and adults. Bear in mind the size of the plant, roots, sun and water needs before you choose your plants. Enjoy the creation..!