A whole wall, ceiling, or other space should not be entirely covered over with rich ornament, and so also in a colored piece of drapery or other ornamental work, it is better to have some portion of it much less rich and of less complicated pattern than the rest, and in some cases to have only a border round a single ground destitute of any pattern, as it is apt to fatigue the eye when overloaded with an equal richness of detail throughout. This is still more important in a colored building, where, if the whole walls, columns, and other parts are covered with elaborate and colored patterns, the eye feels a want of repose, and the same when a building is covered entirely with sculptured ornament without color. The richly carved part not only requires an unsculptured portion in order that it shall not fatigue the eye, but is improved and set off by the contrast, and contrast is as necessary for effect in form, quantity of detail, position of lines, as it is in color. On this principle great effect is sometimes given to a colored pattern by having a portion of the composition on the wall of the building without any color at all, and for the same reason an expanse of wall in a room often looks well when painted with a single uniform ground surrounded by a rich pattern.

Again, certain colors are better suited for some places than for others, and the brighter and more transparent for higher positions, and if the hangings of a room are scarlet, crimson with gold has a richer and better effect for chairs than scarlet and gold. A carpet may be darker than the general tone of the draperies, and some of its colors may be carried up by the walls or the curtains, but if the carpet is dark, the furniture shows better by being of a lighter hue. Red, or a light color, is better than blue for table covers, and though green is not recommended for daylight, it lights up well at night, when blue does not, and this then often appears black, or when of a light tone is scarcely to be distinguished from green. Much, however, may be done to give blue its proper effect, even by artificial light, either by placing a light tone of blue close to the darker one, or by interspersing it with white, which will often lead the eye to see the darker blue, and prevent its appearing black. This may be seen in some Persian carpets where two blues are used. And if some of these have too much green for daylight, they have a good effect at night, except when in excess.

Dark green, like dark blue, looks darker by artificial light.