Colorful fabric curtain on wall/windows as a pop of color to add vibrancy against a white/gray background. Curtain is interchangeable, just like rugs and customized covers for furniture. I love anything that is easily interchangeable and can change the look/feel of an entire space so simply. Maybe red or a brilliant, dark green near the windows around Christmastime to showcase the beautiful wooded views. Colorful reds, pinks, purples, oranges, blues, yellows and greens - like a child's scribbles - in an otherwise white room, will showcase our playfulness and youth, while also serving as a friendly and warm atmosphere for our family... Especially amid the concrete, clean-lined, sparse living area.