In discussing tone contrast it is of course to be remembered that tones, as we have denned the word, are simply measures of relative light and darkness, the idea of hue or color proper being abstracted. We are not in this connection concerned with correct hue relationships, but with correct tone relationships, which is an entirely different matter. Thus it often happens that a color contrast entirely satisfactory as far as the hues are concerned is inharmonious because of bad tone contrast. A dull gold cushion on a dark blue davenport would be pleasing; a cushion of pale maize or primrose would not be.
Tone contrast is a factor of very great importance in interior decoration. Necessarily an element in every decorative problem, it must be carefully studied and skillfully employed. When so employed it becomes a source of beauty; when otherwise employed a source of discord and unrest. Nowhere in the art do we find a stronger confirmation of the statement that good decoration is not absolute but relative, and that the essential thing is correct relationship; for it constantly happens that a color, pleasing in itself, is so changed in tone by contiguous colors that it becomes unpleasing. The pastel or water color that blends rest fully into the background of a soft gray wall will seem to start violently from a dark wall. The low-toned Kurdistan rug that rests as peacefully upon a dark floor as if it had grown there will ruin the repose of any room in which it is placed upon a floor of light yellow oak or maple.
Contrast of tone, like contrast of line, form or hue, is essential in good decoration because it helps to ensure the diversity without which beauty is impossible. Thus tone contrast is necessary between floor and wall, wall and ceiling, background and ornament, and between the structural and non-structural parts of a room. It is however a serious mistake to make these contrasts too marked, since they inevitably tend to arouse a sense of activity and hence to be destructive of repose. Many rooms have been spoiled by too sharp contrast between floor and wall, and many more by too sharp contrast between wall and ceiling-the latter defect being very common by reason of the widespread but erroneous idea that the ceiling must always be either white or a pale cream, regardless of the tone of the walls.
Bad tone contrast appears most frequently, however, and in the form most destructive of repose and beauty, in sharp contrasts between small masses, or between a small and a large mass. The motive in carpet or wall paper which is markedly lighter or darker than its back-ground, and therefore appears to stand out in a definite effect of relief; the ebony piano against putty-colored walls, or the large mahogany dresser against pearl or pale French gray; pale-tinted cushions against dark, heavy upholstered furniture; dark verdure tapestry papers in a frieze above white paneled walls-these and a multitude of like offenses against harmonious tone relationships are constantly to be met with.
Monotone is tiresome, and to normal persons unendurable. The eye is never satisfied unless the visual field presents a diversity of tones. However, it must first of all be an orderly diversity, as otherwise the effect would be so incoherent that the mind could recognize essential tonal likenesses only with a sense of effort. Disorder is never an esthetic quality, but is rather the most fecund source of ugliness. If, in order to demonstrate this fact experimentally, one will take five small oblongs of plain neutral gray, say one by two inches in size, and varying progressively in tone from dark to light, and will place these oblongs side by side in every possible combination, it will be found that the only esthetically pleasing arrangement is one in which the tones vary progressively from one extreme to the other. Thus the eye is able to take in the whole series with the least effort, and the mind judges of the nature of each tone, perceives without effort the elements of likeness, and is content.
Orderly tone relationships give atmosphere and coherence and organic unity to a decorative treatment, and are as much as any other single factor responsible for its beauty and charm. In the treatment of background surfaces this orderly arrangement will work upward in an ascending scale, from the floor through the walls to the ceiling. Rooms in which this order is reversed by using darker tones on the walls and ceiling and lighter tones on the floor have in general a topheavy and disturbing appearance, because the mind through age-long processes of association has come instinctively to regard dark-colored forms and surfaces as heavier in weight than light-colored forms and surfaces. Accordingly it wants to see the darker masses below the horizontal center of the room for the sake of stability, with the darkest at the base; and the lighter masses above the horizontal center for the sake of buoyancy and lightness, with the lightest at the top. Thus in a carefully furnished room the three background surfaces, floor, walls and ceiling, constitute three distinct zones, each characterized by a dominant tone quality. Within each of these zones there may be in good work wide contrast both in hue and in purity. There ought not, however, to be any very wide con- trasts in tone, and in general we may say that the less the tranquillity of the zone atmosphere is broken by contrasts of tone, beyond the minimum essential to the proper outline and emphasis of form, the greater will be the chance of beauty in the room.