What goes in must come out. That rings true for what we eat or drink – or the lack thereof. Urine color is one of the body’s indicators if it is receiving enough water. When a person is dehydrated, urine output is decreased and color is darker. Certain diseases (or food!) can change the color or urine completely! Either way, keeping track of what you eat and drink and what comes out of your body after is a must to keep healthy.
Normal urine usually ranges from colorless to pale yellow. The yellow color comes from a substance called bilirubin, which comes from red blood cells. When RBCs are ready to be catabolized (broken down) by the body, bilirubin is one of the end products which is then excreted in urine. When a person is well-hydrated, bilirubin is very diluted, giving urine a very pale, transparent yellow color.
Dark Yellow Urine
When a person doesn’t drink enough water to compensate for the loss through sweating and other body processes, the body starts to decrease urine output to conserve water. Urine becomes more concentrated, giving it a darker yellow color. This is not because your body is producing more bilirubin, it just means that there is less “water” to dilute it. 
Amber or Honey Colored Urine
Amber-colored urine signifies that you are dehydrated – but probably not so much as to cause severe or lasting damage. With proper hydration at home, this can be resolved. Urine can also turn amber in color if you are substituting water with artificially colored fruit juices or sodas, which can turn urine color darker even with adequate amounts of fluid intake. 
Urine turns brown or syrup/beer-like in color with severe dehydration. By this time, urine output is markedly decreased – the body’s attempt to keep water in. Prolonged lack of water causes hypovolemia, where there is a decreased amount of blood circulating in the body. This causes the tissues to be deprived of oxygen, leading to damage. Brown urine can also be caused by damage to the kidneys or liver. 
When urine is bright orange or yellow, it might be an excess of B vitamins – but it can be caused by a liver disease – especially if you also have pale stools, yellow skin, and the whites of your eyes turn yellow. A blockage in the bile ducts can cause too much bilirubin to circulate in the blood, causing the yellow-tinge. 
Pink or Red Urine
Urine that is pink or red in color can be caused by different things: consuming beets or rhubarb, medication like Rifampicin (an antibiotic used to treat pulmonary tuberculosis), or medical conditions causing blood in the urine – for example a urinary tract infection or kidney and bladder stones.  Blood in the urine is a symptom that should not be ignored and medical assistance should be sought at once.
Blue or Green Urine
Blue or green urine is unusual and the cause is usually medicine, such as amitriptyline, indomethacin, and propofol. A rare medical condition called familial benign hypercalcemia (also known as “blue diaper syndrome”) causes children to have blue urine. An infection of the urinary tract with pseudomonas bacteria causes urine to turn green. 
If you notice that your urine output or color has changed to something unusual, seek medical help promptly.
 National Institutes of Health (2015). Urine – abnormal color. http://www.nlm.nih.gov/medlineplus/ency/article/003139.htm
 National Institutes of Health (2015). Bilirubin. http://www.nlm.nih.gov/medlineplus/ency/article/003479.htm
 Mayo Clinic (2014). Urine color. http://www.mayoclinic.org/diseases-conditions/urine-color/basics/symptoms/con-20032831