Color changes in your urine often indicate severe lack of water. If you are well hydrated, your urine should be lightly colored. But, if your body lacks water, your urine will change its color dramatically.
Drink more water than you usually do, if your urine is darker. Different urine colors show your level of hydration. If your urine is brown, you are dealing with severe dehydration.
Be careful, you should not drink several glasses of water at once. This may give you serious problems. Drink your water slowly and carefully, and thus enable the body to distribute it to the required organs.