Since your room gets plenty of sunlight your color options are quite broad.

For your main color, we chose to keep white/off-white as it offers a fresh, clean, feel to the space and fits grate with the concrete elements. White and off-white colors are often a favorite for walls because they are light, neutral, and match most color schemes. They are known to make rooms feel more airy and spacious.

Use an eggshell finish paint which has a very light touch of shine (similar texture to an eggshell as implied by its name). This finish is very often used for walls and is more durable and easier to clean than matte finish