Final answer:
In a fluorescence microscope, molecules adsorb energy from light and emit visible light, resulting in glowing colors against a dark background.
Step-by-step explanation:
In a fluorescence microscope, molecules adsorb energy from light and glow with a bright color or colors against a dark background. This is achieved using fluorescent chromophores called fluorochromes, which absorb energy from a light source and then emit this energy as visible light. The visible color of the fluorescence marks the location of the target molecule or structure in the cell.