Urine is usually a pale yellow to amber color, but it can range from almost colorless to very dark or bright yellow. Urine’s yellow color is caused by the presence of urobilin, a pigment created when bilirubin is broken down in the liver. Bilirubin is a byproduct of the breakdown of old red blood cells.
The amount of urobilin in urine determines its color. Urine that is very light or colorless may indicate dehydration, while very dark or bright yellow urine may indicate an over-concentration of waste products in the urine. Bright yellow urine is typically caused by excess amounts of B vitamins, food coloring, or medications in the system.
It is important to note that urine color is not always an indicator of health. If you notice a change in the color of your urine, it may be a sign of a medical condition or the result of something you ate, drank, or took. If you are concerned about any changes in the color of your urine, it is important to speak to your doctor.