As the colors on the back and front of the rug are almost identical, although they appear somewhat faded, the rug is unlikely to actually have faded.
The producers of oriental tribal and village rugs did not just weave/knot the rugs, but also usually produced the dyes themselves from vegetable matter using various complex chemical processes, and preparing the wool so that it would absorb the dye and be colorfast. Thus the quality of an antique rug depends not just on design and weaving (knotting) but also on the quality of the dyes.
Towards the end of the 19th century, synthetic dyes were introduced from the West, and were taken up by many weavers. These early synthetic dyes were not of good quality, though.
The reds and pinks in your rug may be early synthetic dyes or otherwise poorly produced natural dyes, and the yellow (or yellow-greenish-like) color is also not of high quality.
Generally, the colors lack uniformity, and although some variation (abrash) in colours is a sign of an original tribal or village rug, on your rug it looks more as if the colors were perhaps not completely colorfast to start with.
Cf. colors with those of the rug on the photo attached.
Shereen attached the following image(s):
