Is being “over-hydrated” a medical condition (at least one that you should be concerned about)? If I notice any color at all in my urine, I always go drink a big glass of water. I like to pee clear. (Still another advantage of being male: the ease with which one can check out their urine color.)
Not a doctor, but I wouldn’t worry about over-hydration unless you’re guzzling water within a very short period of time (i.e. something like a gallon in an hour). I am generally never concerned when my urine is light and more concerned when it’s darker. If it’s dark, cloudy, and smelly, that’s a sign that you may have a bacterial infection or some other condition that requires medical attention.
As was posted earlier, what you eat can also change the color of urine. The amount of water you’ve lost, any meds you take, and frequency of urination can change the color as well.
If you’re concerned about kidney function, you could initially try drinking more fluids (water) and a diet with more vegetables and low salt content. Don’t just look at the color of urine but also the output and frequency. If you’re drinking 2-3 liters of water a day but not producing a lot of urine, you’d definitely at least want to consider getting that checked out.
There’s only a risk if you really, really overdo it (medical conditions called hyponatremia and hypokalemia). Like, gallons of water in a 24-hour period. A woman died this way trying to win a contest for a radio station.
Otherwise, if you like clear pee and making unnecessary bathroom trips, knock yourself out.
Some kinds of poisoning, maybe? I read a memoir by a guy who escaped from North Korea, and he wrote about eating all sorts of not-normally-edible plants during the famine, some of which caused their urine to turn blue.
Speaking of Korea, MASH had an episode where the docs wanted to take an officer out of action because he lost a of men by being dumb. They gave him a drug that made his urine blue . Don’t recall the drug name.
I recall the episode where they took out another unit’s “ringer” in a bowling match that way - the dye/drug was methylene blue. I’m not sure that was what they did in the other episode, which sounds like “The General Flipped at Dawn.”
Sometimes the urine will become much darker, with the color of something like maple syrup. This is common when there is jaundice (high levels of bilirubin in the blood due to liver disease). When this happens in conjunction with a lightening (or even whitening) of the stool, it indicates a blockage in or around the liver.
Not really relevant in a thread about urine color changes, but I’ll add that people can actually pass gas in their urine. Basically, they fart through the urethra (the peeing tube). This can happen when there is a fistula (a connection) between the bowel and the urinary system. It’s not all that rare and is surprisingly well-tolerated (physically). A bit more info in this post if you’re interested.