I suppose the most marked example of color as structure is in the Byzantine use of mosaic decoration that becomes architecture. The decoration of the interiors so related to the form that they fuse. In less elaborate interior design this is always the ideal approach to color - used not only as just color alone.
Van Day TruexColor is a major element in scale. A small room can have a larger look by the use of closely related values, hues, and intensity. A large room can be made to look smaller by marked contrasts of color and value, hue, and intensity. Value is one of the most important elements. Whether light or dark, little value contrast makes for unity, and sharper contrast makes for stronger punctuation.
Van Day Truex