Final answer:
Particles of dye mix with water through diffusion, moving from areas of higher concentration to lower ones, leading to an even color distribution.
Step-by-step explanation:
When dye is mixed with water, the behavior of particles observed is due to a process known as diffusion. Diffusion describes the movement of molecules from an area of higher concentration to an area of lower concentration until they are evenly distributed throughout the solution. This behavior is why, over time, the color molecules in food coloring spread throughout the water, eventually resulting in the water adopting an even color. The same principle applies to other substances such as gelatin, glue, starch, and dehydrated milk powder when they contact water and disperse to form colloidal systems.