Layer window treatments in a moody green living room by combining sheer curtains with heavier drapes or textured Roman shades. Start with light-filtering sheers to soften natural light and add privacy while preserving the room’s moody ambiance. Then add lined or patterned drapes in warm tones for depth and insulation. Layering textiles creates softness, adds visual interest, and balances large windows against dark walls and fireplace features effectively.