more concentrated urine in the bladder can be darker. as long as your urine returned to a more-normal light yellow color after you drank more water there is no need to be concerned.
amber colored urine? dehydration? . i had 3 cups of coffee and a red bull today all in 4 hours. the first time i urinated it was an amber color. then i got worried and drank a lot of water and now my urine is back to normal (light yellow). this only happened once after drinking all that caffeine.