One thing I want to mention are the creases in the middle of the bed. Since they are folds of the sheets, there should be highlights on the side towards the window. Every fold (or bump) like that will have one side lighter, the other dark (very subtle shades though). Now that the color is only dark, that more implies a crease (a hole), like cracked wood.
And to be consistent with the source of light (assuming the window), the bottom and right edge of the sheet on the bed shouldn't have highlights, but the top and left should. Although that's not a hard rule because it's also down to art style. You can do equally dark outlines, or equally dark outer outlines (but not inner), properly shaded outlines (but darker than local color), no outlines etc. So defining your light source and art style should clear some of the confusion when deciding on outline colors.