To know if you have drunk enough water, the colour of your urine is a good indicator. This chart, courtesy of a bottled water company, helps you spot where you are: one to add to other excreta-related charts! Note that it isn't the first urine colour gradation, but of course adding "Pantone" adds buzz.
I wish they had included "I forgot I ate beetroot a few hours ago and I just got really scared looking into my toilet". See this chart for more exotic colours...Image credits: Highland Spring
Found thanks to: kottke.org