When the weather gets cooler, make sure you stay cozy while sleeping by swapping out your lightweight sheets for a Flannel Sheet Set from Threshold. These cotton flannel sheets will add an extra layer of warmth to your bed, just perfect for a good night's sleep on a chilly evening. With both solid and patterned options, you're sure to find a set that fits with your current bedroom decor. Size: Twin. Color: Sour Cream. Gender: Unisex. Pattern: Marble.