The basic idea is for a towel to dramatically change color if it's too wet to absorb more water. While towels naturally become darker when waterlogged, a more vivid color change would make it immediately visually apparent whether a towel is useful or not.
The more advanced version would change color based on pH and salt levels in the towel, telling the bachelor owner that it's really time to do a load of wash.-- Bartlebooth, Feb 09 2002 Hmmm. This is a cool idea in a Sharper-Image, or Hammacher-Schlemmer kind of way.-- bristolz, Feb 09 2002 Say, that reminds me - the towels were due for their Annual Wash last July-- thumbwax, Feb 09 2002 Color subject to feedback that reminds me, I feel a headache coming on.-- reensure, Feb 10 2002 Is this something like those T-shirts that changed colour to show where you were sweating?-- CoolerKing, Feb 10 2002 how many people are sharing your towel? and how often are you taking a bath?-- nomadic_wonderer, Oct 26 2004 random, halfbakery