Since you are keeping the antique beds their original color and painting the walls linen white, would you consider a wood plank ceiling stained in the same color as the bed posts? You still could keep the white trim and white crown molding, but the dark wood ceiling might make the room look/feel cozy while contrasting from all the white tones. If there is not another window to the right of the second twin bed, would you consider switching the dresser and the beds? The beds do not look quite right without being centered between two windows, and the lower dresser would look nice on the window wall, but to the right of the window as shown in the picture. If you do use a pop of color on the dresser, you might get sheet sets in the same color to tie the color scheme together. Throw pillows and a throw in the accent color would look nice too.