I'd suggest dark red curtains if you need curtains at all -- the windows are beautiful as they are, and I'm not sure whether some kind of blind might not give you the ability to darken the room when you want to. On the wall, if you are real fans of any movies or TV shows, three big posters would be fun. Otherwise, I would still suggest using three pieces of art there of that size, all equal in size and somehow relating to each other. Three floral works, or three works in the same style, perhaps. I think a large plain textured rug in a light neutral from one of the cushion fabrics would tie the space together well. You might also consider a lovely low coffee table on the rug to lay out your snacks and drinks for serious media nights.

In civil engineering this condition is known as efflorescence this condition occurs due to capillary action of water in brick in which water contains diffrent salts comes on surface through voids of brick and evaporates and salt rest on surface as shown in image this salts may be harmful or not this depends on type and chemistry of salts generally it is not harmful

white and browns - forever in style

Keep things cool Cooler shades such as grey and blue help walls recede, making the room feel more spacious and light. Bring home the sunshine Light but warm colours such as terracotta or yellow can mimic sunshine and make a space feel bright and airy. Pale ceilings Keep the ceilings in a light colour to make the room appear larger and lighter. While white is your safest bet, you can opt for mint or sage green for a pop of colour.