Why does a colored liquid mix with clean water if the water is not stirred?

All bodies are made up of molecules and molecules are in constant motion. Mixing two different liquids is a phenomenon called diffusion. Diffusion occurs at any temperature, but faster at high temperatures. Therefore, by pouring two liquids together, we may not stir them. The molecules of one liquid will penetrate between the molecules of another liquid and, within a certain time, the pure water will be colored.