Transfer the water to the pierced container and use the amount of time to drip out as a measured unit of time. Repeat the dripping process as necessary. Wow, lots of fun. Here's one of my favorites. The sun naturally lightens hair, if you spend enough time in it.
Some hair reacts more strongly than others.
Course, I'm in Ohio. Weather affects everything. And there's always the shock legend. Your hair turns white after a fright. Chemicals in the water can change your hair color.