I love the idea of a blue office space, blue is so beautiful, calm and soothing. I’d try to go for a slightly lighter shade of what’s currently on the 2 painted walls, but paint all 4 walls. Maybe even the ceiling if you’re so inclined - it can really elevate the space to have your “5th wall” aka ceiling in a complimentary light color. Don’t forget about making good choices with lighting in regards to your workspace. A standing lamp near your arm chair, a task lamp for your desk… etc. take advantage of any natural light as well. Some bamboo blinds and soft shear curtains or alternatively no blinds and some heavy blackout velvet curtains that you can easily open and close as needed.