About 1868, the crinoline silhouette went out of style. The smooth, distinctly bell-like shape of the crinoline supported skirt began to change form, with the fullness moving towards the back of the shirt. This new skirt shape required a different kind of understructure: the bustle. Essentially a cage crinoline cut in half, the bustle supported the back of the skirt, while leaving the front unsupported. In the early years of the 1870s, the bustle usually extended from the waist to about the mid-calf. A c. 1871 bustle of cotton with metal boning can be found here. The bustle was fashionable until about 1875, when it went out of style as skirts were fitted closer to both the front and back of the body. Beginning about 1883, the bustle enjoyed another round of popularity until finally going entirely out of fashion about 1890.
Though the many elements of our ensemble are constructed from the same fabric, this wasn't always the case. In February 1871, Arthur's Lady's Home Magazine featured two short, swagged and gathered overskirts, both of which could be made of any "fashionable winter materials." Either overskirt could then be worn over another skirt, as long as any trimmings "correspond[ed] with the rest on the costume." This suggests that the overskirt, which required much less fabric, could be worn to update an older ensemble or to extend a limited wardrobe.
Fashion plates indicate that it was not uncommon in the early 1870s for a dress to feature one or more strong, often contrasting colors. This October 1870 fashion plate from Peterson's Magazine pictures five dresses. Of these five, three feature strongly contrasting colors: a green and black walking dress, a purple walking dress with black trim and a pale cream house or walking dress trimmed with black. Note that the dresses at the far left and far right feature scalloped trim similar to the green trimmed scallops on this dress. The red silk house dress at the center of this March 1871 fashion plate from Peterson's Magazine features the same strongly horizontal embellishment seen below. Both fashion plates are part of the Los Angeles Public Library Casey Fashion Plate Collection, a fully searchable archive of British and American fashion plates.