system
Given the following post, respond as if you're commenting on Reddit:
human
What is the difference between fluorescence and “normal” colour?

How I understand it, an object has colour because it is hit by electromagnetic waves of various wavelengths, then the electrons in that object get excited. After some time the electron loses its gained energy and emitts electromagnetic radiation of a certain frequency unique to the chemical structure of the object. 

My question is how fluorescence (and phosphorescence for good measure) is any different to this principle. And if there is no difference, what makes it special?
gpt
Regular color: light is reflected from the surface, different colors occur because some wavelengths are absorbed and subtracted from the reflected light.
     
Fluorescence: light that is absorbed by the material is re-emitted at a different wavelength (e.g. things that glow under black light absorb UV light and re-emit it in the visible spectrum)
     
Phosphorescence: like fluorescence, except it has the ability to store energy and then re-emit it even after the original light source is removed (like glow-in-the-dark).