Why does the yellow in urine sink to the bottom of the toilet bowl?

The yellow color in urine primarily comes from a pigment called urochrome, which is a byproduct of the breakdown of hemoglobin. When urine is expelled, the density and composition can cause the pigment to settle at the bottom of the toilet bowl, particularly if the urine is concentrated. Additionally, the physical properties of the urine, including its viscosity and the presence of other substances, can influence how the pigment disperses and settles.