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.