There is an entire science behind colors, but I will explain it in simpler detail.
The colors you see throughout daily life are only visible to the eye, as light radiates off their surfaces. Without light, there is nothing to see. Paint has metallic particles in it, and sometimes polyesters, which make up the iridescent, ultra violets, pearl and other finishes. And all will change depending on the type of light which it receives. This can sometimes accentuate the highlights on edges and curves, where they appear to transition from light to dark.
Cast solid media, such as solid vinyl plotting is also of a different process. Same for vinyl coverings.
Achieving a perfect 100% color match is near impossible and never offered. However, colors will come close enough, so that it blends in and compliments its surroundings.
I use 6 color solvent processing, which also contains metallic ingredients. Thus, when referring to, or translating and communicating in the language of colors, I suggest using the color chart and its related codes as provided within this page.
Please keep in mind, that all monitors are not created equally, and what you see may appear different on any other given viewing medium or device.