Depending how vivid your scarlet is: You can go with white or cream so it really is the accent wall and nothing is shouting for equal attention You can also go for a muted grey or beige

Your drapes look like they're fine. It's hard to see if they're long enough--do they just touch the floor? That would be the right length. Make sure the paint you pick blends with the color of the drapes and the two chairs. The Edgecomb Gray looks like it would work or you could go with an entirely different color and add pictures and rug to pull it all together. Love the color Sea Salt by SW.

I gave a pics of my house walls pse gave me suggestions which colour paint best house wall outer and inside the living room.

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.