Yes, there are 3D-printed parts which discolor under influence of UV, with varying speeds and intensities.
PA12, PA-GF
Over time, PA12 or PA-GF will start to show discoloration and turn slightly yellowish. Unfortunately, this process is an inherent property of the nylon material and is caused by a chemical reaction within the polymer chains. There is no treatment that can protect the natural color of nylon from discoloring over time completely. You can only delay the process by, for instance, applying a UV-protective finish. As an alternative, we recommend choosing a colored finish for your model like dyeing or spray painting. Please also see the article: What do I need to know about the discoloration of polyamide?
TuskXC2700W, Poly1500, ProtoGen White, Xtreme
Whereas PA12 discolors over time, the epoxy resins used in Stereolithography discolor by direct UV-light more than any other materials. We recommend varnishing in order to slow down discoloration, or painting your model when wanting to keep a consistent color.
TuskXC2700T
When ordering the Transparent finish for our material TuskXC2700T, a clear varnish is applied to your model to enable transparency. The varnish will protect your model from dust and slow down the discoloration process.
Example: The picture above shows a freshly printed ProtoGen White sample on the left, versus a sample of the same material on the right which was exposed to direct sunlight for four days in a row.