Now after considering the difference between direct and reflected light, let us go back to the blue dress. We were saying, you will remember, that the skirt no longer presented an appearance of uniform hue. For the local color of the material had become affected by the way in which the light reached the folds. On the raised edges the blue appears almost white; in the bottom of the hollows, where no light penetrates, it appears to be almost black. Meanwhile on the sloping edges of the folds there are varying degrees of lighter or darker blue, according as the material approaches nearer to the light, or recedes further from it. In other words, the light strikes the surfaces of the dress at different angles; there are varieties of reflections, and some parts of the skirt are almost entirely removed from the action of the light.