Subject: What is the natural color of urine? Is yellow a sign of dehydration?

A student's mother said urine is crystal clear:  no color at all.  
Unless the person is dehydrated, then the urine is a shade of yellow.  
The more dehydrated, the more yellow.  She uses for proof her water 
diet.  She drinks two quarts of water a day and her urine is clear.  
Just what is the "natural" color of urine?

Re: What is the natural color of urine? Is yellow a sign of dehydration?