Copyright of a set of colors?
I often see color combinations on webpages, images, posters, products etc. that harmonize really well. Am I allowed to use those colors in my own design?
This is solely about the colors. I will not use images, logos or shapes from that source, and my content is not related to the original color source. I am also far from any commercial aspect here.
A color or a set of colors can be trademarked under some legal systems, as long as it's "used to perform the trademark function of uniquely identifying the commercial origin of products or services", to quote Wikipedia. For instance the characteristic purple shade of Milka chocolate packages is trademarked in Europe.
Even if not trademarked, it can be argued that coming up with a substantially distinctive set of colors is a creative process and therefore constitutes a piece of work protected by intellectual property rights. Whether this argument would hold in court depends on the case and the court, obviously.