Sunlight, fluorescent, and incandescent light have different effects on perceived color. Metamerism, as it refers to color reproduction in the graphic arts industry, is a situation where to colors with different spectral power distributions appear to be the same color. An example is the conversion of art produced with a variety of oil paints or watercolor pigments that is scanned and accurately reproduced with the CMYK printing process. So metamerism is actually a good thing but it is frequently confused with bronzing or metameric failure.
Metameric failure describes undesirable situations where colors that match under one lighting condition vary when the illumination source changes. It is similar to a translucent pearl paint finish on an automobile reflecting multiple colors at different angles. Though it is physiologically impossible to produce colors that look identical under all light sources, the goal is to minimize deviation. Metameric failure is sometimes observed with inkjet printing on glossy paper. Perhaps what appears to be gray under one light may have a green or blue tint under another. Over the years considerable research has improved the quality of inks and papers to minimize metameric failure and improve metamerism.