Light or Dark Yellow?

At the gym, in the ladies' room (I don't know if it's in the men's... probably) they have this chart on the inner door to the stalls. It's a "urine color chart." Light yellow means you're just fine.... Hydrated, etc. Then it gets darker, to a mustardy color at the bottom that means you're a cactus & should drink like five gallons of water instantly. (I'm exaggerating. That's not really the advice. But close.)

I always wonder if anyone seriously checks this. They hold up the chart after going? And take the advice seriously? I mean, yes, it's hot. One should drink water while exercising. But that chart just seems wrong on so many levels.

And yes, I'm well-hydrated. How about you? Checked lately? ;)