urine and urea

Urine is normally composed of water and wasted products filtered
form the body. The kidney produces urine. The other main function of the
kidney is to regulate fluid balance in the body. It performs this function by
using a selective osmosis system. Basically, the way it works is that
electrolytes (dissolved salts like sodium, potassium, calcium, carbonate,
chloride) are pumped back into or out of urine and blood so that in the end,
just the right amounts of electrolyte and water exit the kidney blood vein.
The rest ends up in urine. Interestingly, normal urine is sterile and has no
bacteria.

Urine chemistry

Chemistry of urine below. If you want to components of urine these are: urea, uric acid, creatinine, sodium, potassium, calcium, magnesium, water, chloride, ammonia, sulphate, phosphate

colors of urine

some kind of materials can change the color of urine is the
vitamin B2 (riboflavin). If you swallow a vitamin B2 supplement, and the amount is more than your body needs, the vitamin is excreted in the urine.
The urine will be a VERY bright yellow - almost fluorescent (except it probably will not glow in the dark). But there is nothing wrong with you when this happens - it is just your body getting rid of extra vitamin B2.
Some health authorities use this as an example that taking large doses of vitamins only makes expensive urine. However, nutritionists who advocate
large vitamin supplementation counter by saying that it is only when the
excess amounts of vitamins spill over into the urine that you know for sure
that your body is getting the maximum amount of the vitamins.